1. WeatherSpark.com
  2. United States
  3. Oregon

Climate and Average Weather Year Round in John Day Oregon, United States

In John Day, the summers are short, hot, dry, and mostly clear and the winters are very cold, snowy, and partly cloudy. Over the course of the year, the temperature typically varies from 27°F to 89°F and is rarely below 11°F or above 97°F.

Based on the tourism score, the best time of year to visit John Day for warm-weather activities is from early July to late August.

Climate in John Day

very coldcoldcoolwarmhotwarmcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow83%83%33%33%clearovercastprecipitation: 1.5 inprecipitation: 1.5 in0.3 in0.3 inmuggy: 0%muggy: 0%0%0%drydrytourism score: 7.2tourism score: 7.20.00.0
John Day weather by month. Click on each chart for more information.

The hot season lasts for 2.7 months, from June 21 to September 12, with an average daily high temperature above 79°F. The hottest month of the year in John Day is July, with an average high of 87°F and low of 56°F.

The cold season lasts for 3.5 months, from November 12 to February 28, with an average daily high temperature below 49°F. The coldest month of the year in John Day is December, with an average low of 28°F and high of 40°F.

Average High and Low Temperature in John Day

Average High and Low Temperature in John DayhotcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FDec 1940°FDec 1940°FAug 289°FAug 289°F27°F27°F57°F57°FJun 2179°FJun 2179°FSep 1279°FSep 1279°FNov 1249°FNov 1249°FFeb 2849°FFeb 2849°F51°F51°F50°F50°F34°F34°F31°F31°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 42°F46°F53°F60°F68°F77°F87°F87°F78°F64°F48°F40°F
Temp. 35°F36°F42°F47°F54°F62°F71°F71°F62°F51°F40°F33°F
Low 28°F29°F33°F37°F43°F49°F56°F55°F49°F40°F33°F28°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 John Day

Average Hourly Temperature in John DayJanFebMarAprMayJunJulAugSepOctNovDec12 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 coldcoldcoldcoolcomfortablewarmhotcomfortablefreezingfreezing
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.

Los Molinos, Spain (5,311 miles away); Yeşilova, Turkey (6,455 miles); and Aydıncık, Turkey (6,387 miles) are the far-away foreign places with temperatures most similar to John Day (view comparison).

Map
Marker
© OpenStreetMap contributors

Compare John Day to another city:

Map

In John Day, 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 John Day begins around June 13 and lasts for 3.8 months, ending around October 5.

The clearest month of the year in John Day is August, during which on average the sky is clear, mostly clear, or partly cloudy 80% of the time.

The cloudier part of the year begins around October 5 and lasts for 8.2 months, ending around June 13.

The cloudiest month of the year in John Day is January, during which on average the sky is overcast or mostly cloudy 65% of the time.

Cloud Cover Categories in John Day

Cloud Cover Categories in John DayclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Jul 2883%Jul 2883%Jan 1633%Jan 1633%Jun 1358%Jun 1358%Oct 558%Oct 558%NowNowclearpartly cloudymostly cloudyovercastmostly clear
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 65%64%63%57%53%39%21%20%31%49%62%65%
Clearer 35%36%37%43%47%61%79%80%69%51%38%35%

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

The wetter season lasts 7.8 months, from October 22 to June 16, with a greater than 17% chance of a given day being a wet day. The month with the most wet days in John Day is December, with an average of 8.2 days with at least 0.04 inches of precipitation.

The drier season lasts 4.2 months, from June 16 to October 22. The month with the fewest wet days in John Day is August, with an average of 2.0 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 John Day is May, with an average of 6.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 24% on May 28.

Daily Chance of Precipitation in John Day

Daily Chance of Precipitation in John DaywetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Dec 1528%Dec 1528%Aug 146%Aug 146%Oct 2217%Oct 2217%Jun 1617%Jun 1617%NowNowrainsnowmixed
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 5.3d5.0d6.1d5.5d6.7d5.0d2.5d2.0d2.3d4.4d6.5d5.7d
Mixed 1.3d0.8d0.5d0.1d0.0d0.0d0.0d0.0d0.0d0.1d0.5d1.5d
Snow 0.7d0.5d0.1d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.3d1.0d
Any 7.3d6.2d6.6d5.7d6.7d5.0d2.5d2.0d2.3d4.5d7.3d8.2d

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. John Day experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 9.2 months, from September 29 to July 3, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in John Day is December, with an average rainfall of 1.2 inches.

The rainless period of the year lasts for 2.8 months, from July 3 to September 29. The month with the least rain in John Day is August, with an average rainfall of 0.3 inches.

Average Monthly Rainfall in John Day

Average Monthly Rainfall in John DayrainrainJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.0 in0.5 in0.5 in1.0 in1.0 in1.5 in1.5 in2.0 in2.0 in2.5 in2.5 in3.0 in3.0 in3.5 in3.5 inDec 51.3 inDec 51.3 inJul 310.3 inJul 310.3 inMay 201.2 inMay 201.2 inMar 110.9 inMar 110.9 inSep 290.5 inSep 290.5 inJul 30.5 inJul 30.5 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″0.9″0.9″0.8″1.2″0.9″0.4″0.3″0.4″0.7″1.2″1.2″

Snowfall

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

The snowy period of the year lasts for 3.2 months, from November 14 to February 22, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in John Day is December, with an average snowfall of 2.9 inches.

The snowless period of the year lasts for 8.8 months, from February 22 to November 14. The least snow falls around July 31, with an average total accumulation of 0.0 inches.

Average Monthly Snowfall in John Day

Average Monthly Snowfall in John DaysnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in2 in2 in4 in4 in6 in6 in8 in8 in10 in10 inDec 253.0 inDec 253.0 inJul 310.0 inJul 310.0 inFeb 221.0 inFeb 221.0 inNowNow
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 2.1″1.3″0.3″0.1″0.0″0.0″0.0″0.0″0.0″0.1″1.0″2.9″

The length of the day in John Day varies significantly over the course of the year. In 2024, the shortest day is December 21, with 8 hours, 50 minutes of daylight; the longest day is June 20, with 15 hours, 33 minutes of daylight.

Hours of Daylight and Twilight in John Day

Hours of Daylight and Twilight in John DayJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 8 minMar 1912 hr, 8 minMar 1915 hr, 33 minJun 2015 hr, 33 minJun 2012 hr, 11 minSep 2212 hr, 11 minSep 228 hr, 50 minDec 218 hr, 50 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 9.3h10.5h12.0h13.5h14.8h15.5h15.1h13.9h12.5h10.9h9.6h8.9h

The earliest sunrise is at 5:10 AM on June 14, and the latest sunrise is 2 hours, 25 minutes later at 7:35 AM on November 2. The earliest sunset is at 4:16 PM on December 9, and the latest sunset is 4 hours, 28 minutes later at 8:44 PM on June 25.

Daylight saving time (DST) is observed in John Day 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 John Day

Sunrise & Sunset with Twilight and Daylight Saving Time in John DayJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:10 AMJun 145:10 AM8:44 PMJun 258:44 PMJun 25Dec 94:16 PMDec 94:16 PM7:35 AMNov 27:35 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 John Day

Solar Elevation and Azimuth in John DayJanFebMarAprMayJunJulAugSepOctNovDec12 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 AM000101010102020203030304040506000010101020202020303040405050602269NowNow
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 John Day

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.

The perceived humidity level in John Day, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

Humidity Comfort Levels in John Day

Humidity Comfort Levels in John DayJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Feb 10%Feb 10%Jul 100%Jul 100%NowNowdrydry
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 0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d

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 John Day experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.5 months, from October 30 to May 14, with average wind speeds of more than 5.5 miles per hour. The windiest month of the year in John Day is December, with an average hourly wind speed of 6.3 miles per hour.

The calmer time of year lasts for 5.5 months, from May 14 to October 30. The calmest month of the year in John Day is August, with an average hourly wind speed of 4.8 miles per hour.

Average Wind Speed in John Day

Average Wind Speed in John DaywindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph1 mph1 mph2 mph2 mph3 mph3 mph4 mph4 mph5 mph5 mph6 mph6 mph7 mph7 mph8 mph8 mph9 mph9 mph10 mph10 mphDec 26.3 mphDec 26.3 mphAug 104.8 mphAug 104.8 mphMay 145.5 mphMay 145.5 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) 6.26.16.05.85.55.34.94.84.95.36.06.3

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

The wind is most often from the west for 2.8 months, from March 12 to June 6 and for 1.1 months, from September 18 to October 20, with a peak percentage of 43% on March 29. The wind is most often from the north for 3.4 months, from June 6 to September 18, with a peak percentage of 51% on July 20. The wind is most often from the south for 4.7 months, from October 20 to March 12, with a peak percentage of 54% on January 1.

Wind Direction in John Day

Wind Direction in John DaySWNWSJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestsouthnortheast
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).

To characterize how pleasant the weather is in John Day 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 John Day for general outdoor tourist activities is from early July to late August, with a peak score in the last week of July.

Tourism Score in John Day

Tourism Score in John Daybest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810107.27.20.00.0NowNowtemperaturetemperaturecloudscloudsprecipitationprecipitationtourism 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 John Day for hot-weather activities is from mid July to mid August, with a peak score in the last week of July.

Beach/Pool Score in John Day

Beach/Pool Score in John DayJanFebMarAprMayJunJulAugSepOctNovDec002244668810103.73.70.00.0NowNowtemperaturetemperaturecloudscloudsprecipitationprecipitation
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 John Day typically lasts for 5.5 months (168 days), from around April 29 to around October 14, rarely starting before April 7 or after May 20, and rarely ending before September 28 or after November 1.

Time Spent in Various Temperature Bands and the Growing Season in John Day

Time Spent in Various Temperature Bands and the Growing Season in John Daygrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Apr 2950%Apr 2950%Oct 1450%Oct 1450%May 2090%May 2090%Sep 2890%Sep 2890%Apr 710%Apr 710%Nov 110%Nov 110%0%Feb 80%Feb 8Jul 28100%Jul 28100%NowNowfreezingvery coldcoldcoolcomfortablewarmhotfrigid
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 John Day should appear around April 18, only rarely appearing before April 1 or after May 9.

Growing Degree Days in John Day

Growing Degree Days in John DayJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F500°F500°F1,000°F1,000°F1,500°F1,500°F2,000°F2,000°F2,500°F2,500°FApr 1889°FApr 1889°FJul 10900°FJul 10900°FAug 221,800°FAug 221,800°FDec 312,525°FDec 312,525°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 3.1 months, from May 19 to August 22, with an average daily incident shortwave energy per square meter above 6.7 kWh. The brightest month of the year in John Day is July, with an average of 7.9 kWh.

The darker period of the year lasts for 3.6 months, from October 28 to February 15, with an average daily incident shortwave energy per square meter below 2.8 kWh. The darkest month of the year in John Day is December, with an average of 1.5 kWh.

Average Daily Incident Shortwave Solar Energy in John Day

Average Daily Incident Shortwave Solar Energy in John DaybrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWh10 kWh10 kWhJul 128.0 kWhJul 128.0 kWhDec 251.5 kWhDec 251.5 kWhMay 196.7 kWhMay 196.7 kWhAug 226.7 kWhAug 226.7 kWhOct 282.8 kWhOct 282.8 kWhFeb 152.8 kWhFeb 152.8 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) 1.82.74.05.56.67.57.96.95.33.52.01.5

For the purposes of this report, the geographical coordinates of John Day are 44.416 deg latitude, -118.953 deg longitude, and 3,084 ft elevation.

The topography within 2 miles of John Day contains very significant variations in elevation, with a maximum elevation change of 1,093 feet and an average elevation above sea level of 3,406 feet. Within 10 miles contains very significant variations in elevation (5,171 feet). Within 50 miles also contains extreme variations in elevation (7,244 feet).

The area within 2 miles of John Day is covered by shrubs (92%), within 10 miles by shrubs (69%) and trees (26%), and within 50 miles by shrubs (61%) and trees (35%).

This report illustrates the typical weather in John Day, 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 John Day.

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