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Climate and Average Weather Year Round in Oak Forest Illinois, United States

In Oak Forest, the summers are warm, humid, and wet; the winters are freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 19°F to 84°F and is rarely below 0°F or above 92°F.

Based on the tourism score, the best time of year to visit Oak Forest for warm-weather activities is from mid June to mid September.

Climate in Oak Forest

very coldcoldcoolwarmcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow69%69%41%41%clearovercastprecipitation: 3.8 inprecipitation: 3.8 in1.2 in1.2 inmuggy: 45%muggy: 45%0%0%drydrytourism score: 6.8tourism score: 6.80.00.0
Oak Forest weather by month. Click on each chart for more information.

The warm season lasts for 3.8 months, from May 25 to September 19, with an average daily high temperature above 73°F. The hottest month of the year in Oak Forest is July, with an average high of 83°F and low of 66°F.

The cold season lasts for 3.1 months, from November 30 to March 2, with an average daily high temperature below 42°F. The coldest month of the year in Oak Forest is January, with an average low of 19°F and high of 32°F.

Average High and Low Temperature in Oak Forest

Average High and Low Temperature in Oak ForestwarmcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FJan 2932°FJan 2932°FJul 1884°FJul 1884°F19°F19°F67°F67°FMay 2573°FMay 2573°FSep 1973°FSep 1973°FNov 3042°FNov 3042°FMar 242°FMar 242°F54°F54°F55°F55°F29°F29°F28°F28°FNowNow
The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.
AverageJanFebMarAprMayJunJulAugSepOctNovDec
High 32°F36°F48°F60°F71°F80°F83°F81°F74°F62°F49°F36°F
Temp. 25°F28°F38°F50°F60°F70°F74°F73°F65°F53°F41°F29°F
Low 19°F23°F32°F42°F52°F61°F66°F64°F56°F45°F35°F24°F

The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in Oak Forest

Average Hourly Temperature in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMNowNowfreezingvery coldvery coldcoldcoldcoolcoolcomfortablewarm
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Damāvand, Iran (6,527 miles away) is the far-away foreign place with temperatures most similar to Oak Forest (view comparison).

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In Oak Forest, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Oak Forest begins around June 12 and lasts for 4.4 months, ending around October 26.

The clearest month of the year in Oak Forest is August, during which on average the sky is clear, mostly clear, or partly cloudy 67% of the time.

The cloudier part of the year begins around October 26 and lasts for 7.6 months, ending around June 12.

The cloudiest month of the year in Oak Forest is January, during which on average the sky is overcast or mostly cloudy 57% of the time.

Cloud Cover Categories in Oak Forest

Cloud Cover Categories in Oak ForestclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Aug 2569%Aug 2569%Dec 2841%Dec 2841%Jun 1255%Jun 1255%Oct 2656%Oct 2656%NowNowclearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.
FractionJanFebMarAprMayJunJulAugSepOctNovDec
Cloudier 57%56%53%51%50%43%36%33%34%41%51%57%
Clearer 43%44%47%49%50%57%64%67%66%59%49%43%

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Oak Forest varies throughout the year.

The wetter season lasts 7.1 months, from March 27 to October 30, with a greater than 26% chance of a given day being a wet day. The month with the most wet days in Oak Forest is June, with an average of 10.9 days with at least 0.04 inches of precipitation.

The drier season lasts 4.9 months, from October 30 to March 27. The month with the fewest wet days in Oak Forest is January, with an average of 5.1 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Oak Forest is June, with an average of 10.9 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 38% on May 28.

Daily Chance of Precipitation in Oak Forest

Daily Chance of Precipitation in Oak ForestwetdrydryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%May 2838%May 2838%Jan 3015%Jan 3015%Mar 2726%Mar 2726%Oct 3026%Oct 3026%NowNowrainsnow
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).
Days ofJanFebMarAprMayJunJulAugSepOctNovDec
Rain 2.6d2.6d5.8d8.7d10.9d10.9d11.2d10.4d8.6d7.9d6.5d4.1d
Mixed 0.7d0.7d0.8d0.1d0.0d0.0d0.0d0.0d0.0d0.0d0.4d0.9d
Snow 1.8d1.5d0.6d0.1d0.0d0.0d0.0d0.0d0.0d0.0d0.1d1.2d
Any 5.1d4.9d7.2d9.0d10.9d10.9d11.2d10.4d8.6d8.0d7.1d6.2d

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Oak Forest experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Oak Forest. The month with the most rain in Oak Forest is June, with an average rainfall of 3.6 inches.

The month with the least rain in Oak Forest is January, with an average rainfall of 1.0 inches.

Average Monthly Rainfall in Oak Forest

Average Monthly Rainfall in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in1 in1 in2 in2 in3 in3 in4 in4 in5 in5 in6 in6 in7 in7 inJun 13.8 inJun 13.8 inJan 280.8 inJan 280.8 inAug 43.5 inAug 43.5 inNowNow
The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall.
JanFebMarAprMayJunJulAugSepOctNovDec
Rainfall 1.0″1.0″1.8″3.0″3.5″3.6″3.4″3.5″3.0″2.7″2.4″1.5″

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Oak Forest experiences some seasonal variation in monthly snowfall.

The snowy period of the year lasts for 4.2 months, from November 20 to March 27, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Oak Forest is February, with an average snowfall of 4.0 inches.

The snowless period of the year lasts for 7.8 months, from March 27 to November 20. The least snow falls around July 21, with an average total accumulation of 0.0 inches.

Average Monthly Snowfall in Oak Forest

Average Monthly Snowfall in Oak ForestsnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in2 in2 in4 in4 in6 in6 in8 in8 in10 in10 inFeb 124.0 inFeb 124.0 inJul 210.0 inJul 210.0 inNov 201.0 inNov 201.0 inMar 271.0 inMar 271.0 in
The average snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.
JanFebMarAprMayJunJulAugSepOctNovDec
Snowfall 3.6″4.0″1.9″0.2″0.0″0.0″0.0″0.0″0.0″0.1″0.7″3.2″

The length of the day in Oak Forest varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 10 minutes of daylight; the longest day is June 20, with 15 hours, 12 minutes of daylight.

Hours of Daylight and Twilight in Oak Forest

Hours of Daylight and Twilight in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 8 minMar 1912 hr, 8 minMar 1915 hr, 12 minJun 2015 hr, 12 minJun 2012 hr, 11 minSep 2212 hr, 11 minSep 229 hr, 10 minDec 219 hr, 10 minDec 21nightnightdayNowNow
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.
Hours ofJanFebMarAprMayJunJulAugSepOctNovDec
Daylight 9.6h10.6h12.0h13.4h14.6h15.1h14.8h13.8h12.4h11.0h9.8h9.2h

The earliest sunrise is at 5:16 AM on June 14, and the latest sunrise is 2 hours, 9 minutes later at 7:24 AM on November 2. The earliest sunset is at 4:20 PM on December 8, and the latest sunset is 4 hours, 9 minutes later at 8:29 PM on June 26.

Daylight saving time (DST) is observed in Oak Forest during 2024, starting in the spring on March 10, lasting 7.8 months, and ending in the fall on November 3.

Sunrise & Sunset with Twilight and Daylight Saving Time in Oak Forest

Sunrise & Sunset with Twilight and Daylight Saving Time in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:16 AMJun 145:16 AM8:29 PMJun 268:29 PMJun 26Dec 84:20 PMDec 84:20 PM7:24 AMNov 27:24 AMNov 2Mar 10DSTMar 10DSTDSTNov 3DSTNov 3daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day over the course of the year 2024. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in Oak Forest

Solar Elevation and Azimuth in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AM0001010101020202030303040405050606000010101020202020303040405050602572NowNow
northeastsouthwest
Solar elevation and azimuth over the course of the year 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

Moon Rise, Set & Phases in Oak Forest

The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Oak Forest experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.7 months, from May 28 to September 20, during which time the comfort level is muggy, oppressive, or miserable at least 11% of the time. The month with the most muggy days in Oak Forest is July, with 13.1 days that are muggy or worse.

The least muggy day of the year is February 5, when muggy conditions are essentially unheard of.

Humidity Comfort Levels in Oak Forest

Humidity Comfort Levels in Oak ForestmuggyJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Feb 50%Feb 50%Jul 2645%Jul 2645%May 2811%May 2811%Sep 2011%Sep 2011%NowNowoppressiveoppressivemuggymuggycomfortablecomfortabledrydryhumidhumid
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.
JanFebMarAprMayJunJulAugSepOctNovDec
Muggy days 0.0d0.0d0.0d0.1d1.9d7.3d13.1d11.8d4.7d0.5d0.0d0.0d

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Oak Forest experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.6 months, from October 1 to May 20, with average wind speeds of more than 10.4 miles per hour. The windiest month of the year in Oak Forest is January, with an average hourly wind speed of 12.9 miles per hour.

The calmer time of year lasts for 4.4 months, from May 20 to October 1. The calmest month of the year in Oak Forest is August, with an average hourly wind speed of 8.1 miles per hour.

Average Wind Speed in Oak Forest

Average Wind Speed in Oak ForestwindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mph16 mph16 mph18 mph18 mph20 mph20 mphJan 1513.0 mphJan 1513.0 mphAug 27.8 mphAug 27.8 mphOct 110.4 mphOct 110.4 mphMay 2010.4 mphMay 2010.4 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Wind Speed (mph) 12.912.612.612.210.69.28.28.19.511.112.312.4

The predominant average hourly wind direction in Oak Forest varies throughout the year.

The wind is most often from the north for 1.4 months, from March 6 to April 19, with a peak percentage of 28% on March 9. The wind is most often from the south for 7.0 months, from April 19 to November 19, with a peak percentage of 37% on September 6. The wind is most often from the west for 3.6 months, from November 19 to March 6, with a peak percentage of 41% on January 1.

Wind Direction in Oak Forest

Wind Direction in Oak ForestWNSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestsoutheastnorth
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Oak Forest is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.7 months, from July 2 to September 24, with an average temperature above 65°F. The month of the year in Oak Forest with the warmest water is August, with an average temperature of 72°F.

The time of year with cooler water lasts for 4.8 months, from December 13 to May 5, with an average temperature below 42°F. The month of the year in Oak Forest with the coolest water is February, with an average temperature of 35°F.

Average Water Temperature in Oak Forest

Average Water Temperature in Oak ForestwarmcoolJanFebMarAprMayJunJulAugSepOctNovDec30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°FAug 1173°FAug 1173°F35°FFeb 2835°FFeb 28Jul 265°FJul 265°FSep 2465°FSep 2465°FDec 1342°FDec 1342°FMay 542°FMay 542°FNowNow
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.
WaterJanFebMarAprMayJunJulAugSepOctNovDec
Temperature 38°F35°F36°F39°F45°F57°F69°F72°F67°F58°F49°F42°F

To characterize how pleasant the weather is in Oak Forest throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Oak Forest for general outdoor tourist activities is from mid June to mid September, with a peak score in the last week of August.

Tourism Score in Oak Forest

Tourism Score in Oak Forestbest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810106.86.80.00.0NowNowtemperaturetemperature cloudscloudsprecipitationprecipitationtourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Oak Forest for hot-weather activities is from late June to late August, with a peak score in the last week of July.

Beach/Pool Score in Oak Forest

Beach/Pool Score in Oak Forestbest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810105.65.60.00.0NowNowtemperaturetemperature cloudscloudsprecipitationprecipitationbeach/pool score
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Oak Forest typically lasts for 6.3 months (191 days), from around April 13 to around October 22, rarely starting before March 28 or after April 30, and rarely ending before October 1 or after November 12.

Time Spent in Various Temperature Bands and the Growing Season in Oak Forest

Time Spent in Various Temperature Bands and the Growing Season in Oak Forestgrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Apr 1350%Apr 1350%Oct 2250%Oct 2290%Apr 3090%Apr 3090%Oct 190%Oct 110%Mar 2810%Mar 2810%Nov 1210%Nov 120%Feb 50%Feb 5Jul 16100%Jul 16100%freezingvery coldcoolcomfortablewarmcoldhot
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Oak Forest should appear around April 10, only rarely appearing before March 26 or after April 25.

Growing Degree Days in Oak Forest

Growing Degree Days in Oak ForestJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F500°F500°F1,000°F1,000°F1,500°F1,500°F2,000°F2,000°F2,500°F2,500°F3,000°F3,000°F3,500°F3,500°FApr 1089°FApr 1089°FJun 19900°FJun 19900°FJul 281,800°FJul 281,800°FDec 313,271°FDec 313,271°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.5 months, from May 4 to August 21, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest month of the year in Oak Forest is June, with an average of 6.7 kWh.

The darker period of the year lasts for 3.3 months, from November 2 to February 11, with an average daily incident shortwave energy per square meter below 2.7 kWh. The darkest month of the year in Oak Forest is December, with an average of 1.7 kWh.

Average Daily Incident Shortwave Solar Energy in Oak Forest

Average Daily Incident Shortwave Solar Energy in Oak ForestbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWhJun 306.9 kWhJun 306.9 kWhDec 211.7 kWhDec 211.7 kWhMay 45.9 kWhMay 45.9 kWhAug 215.9 kWhAug 215.9 kWhNov 22.7 kWhNov 22.7 kWhFeb 112.7 kWhFeb 112.7 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Solar Energy (kWh) 2.02.94.15.36.26.76.76.04.93.52.21.7

For the purposes of this report, the geographical coordinates of Oak Forest are 41.603 deg latitude, -87.744 deg longitude, and 669 ft elevation.

The topography within 2 miles of Oak Forest contains only modest variations in elevation, with a maximum elevation change of 121 feet and an average elevation above sea level of 660 feet. Within 10 miles also contains only modest variations in elevation (220 feet). Within 50 miles contains only modest variations in elevation (653 feet).

The area within 2 miles of Oak Forest is covered by artificial surfaces (89%), within 10 miles by artificial surfaces (83%) and trees (10%), and within 50 miles by cropland (46%) and artificial surfaces (27%).

This report illustrates the typical weather in Oak Forest, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Oak Forest.

For each station, the records are corrected for the elevation difference between that station and Oak Forest according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Oak Forest is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Oak Forest and a given station.

The stations contributing to this reconstruction are:

To get a sense of how much these sources agree with each other, you can view a comparison of Oak Forest and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © OpenStreetMap contributors.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.

Please review our full terms contained on our Terms of Service page.