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Average Weather in Cairo Illinois, United States

In Cairo, the summers are long, hot, and muggy; the winters are short, very cold, wet, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 29°F to 90°F and is rarely below 14°F or above 97°F.

Climate Summary

70%70%47%47%clearovercastprecipitation: 4.8 inprecipitation: 4.8 in2.4 in2.4 inmuggy: 82%muggy: 82%0%0%drydrycoldcoolwarmhotwarmcoolcoldtourism score: 6.2tourism score: 6.20.50.5JanFebMarAprMayJunJulAugSepOctNovDec
Click on each chart for more information.

Based on the tourism score, the best times of year to visit Cairo for warm-weather activities are from early May to late June and from late July to early October.

Temperature

The hot season lasts for 3.9 months, from May 21 to September 19, with an average daily high temperature above 81°F. The hottest day of the year is July 5, with an average high of 90°F and low of 71°F.

The cold season lasts for 3.0 months, from November 29 to February 27, with an average daily high temperature below 54°F. The coldest day of the year is January 22, with an average low of 29°F and high of 45°F.

Average High and Low Temperature

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.

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

Average Hourly Temperature in CairoJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMcomfortablewarmhotcoldcoolvery coldfreezing
The average hourly temperature, color coded into bands: 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 shaded overlays indicate night and civil twilight.

Clouds

In Cairo, 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 Cairo begins around June 15 and lasts for 4.7 months, ending around November 4. On August 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 70% of the time, and overcast or mostly cloudy 30% of the time.

The cloudier part of the year begins around November 4 and lasts for 7.3 months, ending around June 15. On December 27, the cloudiest day of the year, the sky is overcast or mostly cloudy 53% of the time, and clear, mostly clear, or partly cloudy 47% of the time.

Cloud Cover Categories

Cloud Cover Categories in CairoclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Aug 2370%Aug 2370%Dec 2747%Dec 2747%Jun 1558%Jun 1558%Nov 458%Nov 458%clearmostly clearpartly cloudymostly cloudyovercast
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

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

The wetter season lasts 4.6 months, from March 20 to August 9, with a greater than 31% chance of a given day being a wet day. The chance of a wet day peaks at 39% on May 11.

The drier season lasts 7.4 months, from August 9 to March 20. The smallest chance of a wet day is 22% on January 27.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 39% on May 11.

Daily Chance of Precipitation

Daily Chance of Precipitation in CairowetdrydryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%May 1139%May 1139%Jan 2722%Jan 2722%Jan 126%Jan 126%Mar 2031%Mar 2031%Aug 931%Aug 931%rainsnow
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).

Rainfall

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. Cairo experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Cairo. The most rain falls during the 31 days centered around April 30, with an average total accumulation of 4.8 inches.

The least rain falls around August 22, with an average total accumulation of 2.4 inches.

Average Monthly Rainfall

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 liquid-equivalent snowfall.

Snowfall

We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

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

The snowy period of the year lasts for 3.2 months, from December 1 to March 9, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 29, with an average total liquid-equivalent accumulation of 0.3 inches.

The snowless period of the year lasts for 8.8 months, from March 9 to December 1. The least snow falls around July 10, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

The average liquid-equivalent 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.

Sun

The length of the day in Cairo varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 37 minutes of daylight; the longest day is June 20, with 14 hours, 42 minutes of daylight.

Hours of Daylight and Twilight

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.

The earliest sunrise is at 5:36 AM on June 12, and the latest sunrise is 1 hour, 48 minutes later at 7:24 AM on November 4. The earliest sunset is at 4:39 PM on December 6, and the latest sunset is 3 hours, 41 minutes later at 8:20 PM on June 28.

Daylight saving time (DST) is observed in Cairo during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time in CairoJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 125:36 AMJun 125:36 AM8:20 PMJun 288:20 PMJun 28Dec 64:39 PMDec 64:39 PM7:24 AMNov 47:24 AMNov 4Mar 12DSTMar 12DSTDSTNov 5DSTNov 5daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of the year 2017. 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.

Humidity

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.

Cairo experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 4.4 months, from May 14 to September 27, during which time the comfort level is muggy, oppressive, or miserable at least 21% of the time. The muggiest day of the year is July 22, with muggy conditions 82% of the time.

The least muggy day of the year is January 14, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels in CairomuggyJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jan 140%Jan 140%82%Jul 2282%Jul 22May 1421%May 1421%Sep 2721%Sep 2721%humidhumiddrydrymuggymuggymiserablemiserableoppressiveoppressivecomfortablecomfortable
The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

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 Cairo experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.2 months, from October 17 to May 24, with average wind speeds of more than 8.3 miles per hour. The windiest day of the year is April 1, with an average hourly wind speed of 10.6 miles per hour.

The calmer time of year lasts for 4.8 months, from May 24 to October 17. The calmest day of the year is July 31, with an average hourly wind speed of 6.0 miles per hour.

Average Wind Speed

Average Wind Speed in CairowindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mphApr 110.6 mphApr 110.6 mphJul 316.0 mphJul 316.0 mphOct 178.3 mphOct 178.3 mphMay 248.3 mphMay 248.3 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

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

The wind is most often from the north for 2.3 months, from January 3 to March 13, with a peak percentage of 36% on February 19. The wind is most often from the south for 9.7 months, from March 13 to January 3, with a peak percentage of 34% on January 1.

Wind Direction

Wind Direction in CairoNSJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%northsoutheastwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Best Time of Year to Visit

To characterize how pleasant the weather is in Cairo 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 times of year to visit Cairo for general outdoor tourist activities are from early May to late June and from late July to early October, with a peak score in the first week of September.

Tourism Score

Tourism Score in Cairobest timebest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.26.20.50.55.85.85.35.3 precipitationprecipitationcloudscloudstemperaturetemperaturetourism 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 Cairo for hot-weather activities is from early June to early September, with a peak score in the last week of July.

Beach/Pool Score

Beach/Pool Score in Cairobest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.06.00.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturebeach/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.

Growing Season

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 Cairo typically lasts for 7.0 months (214 days), from around March 31 to around October 30, rarely starting before March 9 or after April 19, and rarely ending before October 12 or after November 18.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Cairogrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Mar 3150%Mar 3150%Oct 3050%Oct 3090%Apr 1990%Apr 1990%Oct 1290%Oct 1210%Mar 910%Mar 910%Nov 1810%Nov 180%Dec 220%Dec 22Jul 13100%Jul 13100%comfortablewarmhotcoldcoolfreezingvery coldfrigid
The percentage of time spent in various temperature bands: 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 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 Cairo should appear around March 4, only rarely appearing before February 13 or after March 21.

Growing Degree Days

The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

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 significant seasonal variation over the course of the year.

The brighter period of the year lasts for 4.4 months, from April 20 to August 31, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest day of the year is July 4, with an average of 6.7 kWh.

The darker period of the year lasts for 3.0 months, from November 9 to February 7, with an average daily incident shortwave energy per square meter below 3.1 kWh. The darkest day of the year is December 23, with an average of 2.2 kWh.

Average Daily Incident Shortwave Solar Energy

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Cairo are 37.005 deg latitude, -89.176 deg longitude, and 308 ft elevation.

The topography within 2 miles of Cairo is essentially flat, with a maximum elevation change of 69 feet and an average elevation above sea level of 305 feet. Within 10 miles is essentially flat (210 feet). Within 50 miles contains only modest variations in elevation (856 feet).

The area within 2 miles of Cairo is covered by cropland (33%), water (29%), herbaceous vegetation (21%), and artificial surfaces (16%), within 10 miles by cropland (68%) and water (11%), and within 50 miles by cropland (66%) and trees (26%).

Data Sources

This report illustrates the typical weather in Cairo, 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Cairo.

For each station, the records are corrected for the elevation difference between that station and Cairo 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 Cairo is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Cairo and a given station.

The stations contributing to this reconstruction are: Cairo Airport (89%, 8 kilometers, northwest); Barkley Regional Airport (8%, 36 kilometers, east); and Everett-Stewart Regional Airport (3.0%, 72 kilometers, south).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

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.