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Climate and Average Weather Year Round at Cottonwood Pass Colorado, United States

At Cottonwood Pass, the summers are comfortable and dry; the winters are long, freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 13°F to 73°F and is rarely below -1°F or above 80°F.

Based on the tourism score, the best time of year to visit Cottonwood Pass for warm-weather activities is from late June to early August.

Climate at Cottonwood Pass

very coldcoldcoolcomfortablecoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow77%77%57%57%clearovercastprecipitation: 1.3 inprecipitation: 1.3 in0.3 in0.3 inmuggy: 0%muggy: 0%drydrytourism score: 5.1tourism score: 5.10.00.0
Cottonwood Pass weather by month. Click on each chart for more information.

The warm season lasts for 3.3 months, from June 2 to September 12, with an average daily high temperature above 65°F. The hottest month of the year at Cottonwood Pass is July, with an average high of 73°F and low of 49°F.

The cold season lasts for 3.9 months, from November 18 to March 14, with an average daily high temperature below 42°F. The coldest month of the year at Cottonwood Pass is January, with an average low of 13°F and high of 35°F.

Average High and Low Temperature at Cottonwood Pass

Average High and Low Temperature at Cottonwood PasswarmcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FJan 2735°FJan 2735°FJul 773°FJul 773°F13°F13°F49°F49°FJun 265°FJun 265°FSep 1265°FSep 1265°FNov 1842°FNov 1842°FMar 1442°FMar 1442°F41°F41°F42°F42°F22°F22°F22°F22°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 35°F36°F42°F49°F59°F69°F73°F71°F64°F54°F43°F35°F
Temp. 24°F25°F31°F37°F46°F57°F61°F59°F52°F42°F32°F24°F
Low 13°F15°F22°F28°F36°F44°F49°F48°F41°F32°F23°F15°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 at Cottonwood Pass

Average Hourly Temperature at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec12 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 AMNowNowfreezingfreezingvery coldvery coldcoldcoolcomfortablecool
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.

Gračanica, Bosnia & Herzegovina (5,773 miles away) and Chepelare, Bulgaria (6,082 miles) are the far-away foreign places with temperatures most similar to Cottonwood Pass (view comparison).

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At Cottonwood Pass, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year at Cottonwood Pass begins around August 29 and lasts for 2.1 months, ending around November 2.

The clearest month of the year at Cottonwood Pass is September, during which on average the sky is clear, mostly clear, or partly cloudy 74% of the time.

The cloudier part of the year begins around November 2 and lasts for 9.8 months, ending around August 29.

The cloudiest month of the year at Cottonwood Pass is March, during which on average the sky is overcast or mostly cloudy 41% of the time.

Cloud Cover Categories at Cottonwood Pass

Cloud Cover Categories at Cottonwood PassclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Sep 2877%Sep 2877%May 657%May 657%Nov 267%Nov 267%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 35%41%41%41%40%30%34%36%26%29%34%35%
Clearer 65%59%59%59%60%70%66%64%74%71%66%65%

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

The wetter season lasts 4.4 months, from April 28 to September 9, with a greater than 19% chance of a given day being a wet day. The month with the most wet days at Cottonwood Pass is August, with an average of 8.2 days with at least 0.04 inches of precipitation.

The drier season lasts 7.6 months, from September 9 to April 28. The month with the fewest wet days at Cottonwood Pass is January, with an average of 2.4 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. Based on this categorization, the most common form of precipitation at Cottonwood Pass changes throughout the year.

Rain alone is the most common for 6.7 months, from April 19 to November 8. The month with the most days of rain alone at Cottonwood Pass is August, with an average of 8.2 days.

Snow alone is the most common for 4.6 months, from November 12 to April 2. The month with the most days of snow alone at Cottonwood Pass is December, with an average of 1.9 days.

Mixed snow and rain is the most common for 3.0 weeks, from April 2 to April 19 and from November 8 to November 12. The month with the most days of mixed snow and rain at Cottonwood Pass is April, with an average of 2.0 days.

Daily Chance of Precipitation at Cottonwood Pass

Daily Chance of Precipitation at Cottonwood PasssnowrainsnowJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Aug 830%Aug 830%Jan 287%Jan 287%Apr 214%Apr 214%Nov 812%Nov 812%Sep 919%Sep 919%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 0.3d0.4d0.8d2.0d3.8d4.1d7.9d8.2d5.3d2.8d0.9d0.4d
Mixed 0.6d0.9d1.2d2.0d1.2d0.1d0.0d0.0d0.2d0.7d1.1d0.6d
Snow 1.6d1.6d1.8d1.1d0.2d0.0d0.0d0.0d0.0d0.4d1.3d1.9d
Any 2.4d2.9d3.8d5.0d5.3d4.1d7.9d8.2d5.5d4.0d3.3d2.8d

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. Cottonwood Pass experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 5.8 months, from April 21 to October 15, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain at Cottonwood Pass is August, with an average rainfall of 1.1 inches.

The rainless period of the year lasts for 6.2 months, from October 15 to April 21. The month with the least rain at Cottonwood Pass is January, with an average rainfall of 0.1 inches.

Average Monthly Rainfall at Cottonwood Pass

Average Monthly Rainfall at Cottonwood PassrainJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in1 in1 in2 in2 in3 in3 in4 in4 inJul 301.3 inJul 301.3 inJan 160.1 inJan 160.1 inMay 160.7 inMay 160.7 inOct 150.5 inOct 150.5 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 0.1″0.1″0.2″0.4″0.7″0.6″1.1″1.1″0.9″0.5″0.2″0.1″

Snowfall

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

The snowy period of the year lasts for 7.4 months, from October 6 to May 20, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow at Cottonwood Pass is April, with an average snowfall of 3.8 inches.

The snowless period of the year lasts for 4.6 months, from May 20 to October 6. The least snow falls around July 28, with an average total accumulation of 0.0 inches.

Average Monthly Snowfall at Cottonwood Pass

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 2.7″3.0″3.4″3.8″1.3″0.0″0.0″0.0″0.2″1.6″2.8″3.1″

The length of the day at Cottonwood Pass varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 27 minutes of daylight; the longest day is June 20, with 14 hours, 53 minutes of daylight.

Hours of Daylight and Twilight at Cottonwood Pass

Hours of Daylight and Twilight at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 8 minMar 1912 hr, 8 minMar 1914 hr, 53 minJun 2014 hr, 53 minJun 2012 hr, 10 minSep 2212 hr, 10 minSep 229 hr, 27 minDec 219 hr, 27 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 9.8h10.8h12.0h13.3h14.3h14.8h14.6h13.6h12.4h11.1h10.1h9.5h

The earliest sunrise is at 5:39 AM on June 13, and the latest sunrise is 1 hour, 54 minutes later at 7:33 AM on November 2. The earliest sunset is at 4:42 PM on December 6, and the latest sunset is 3 hours, 51 minutes later at 8:33 PM on June 27.

Daylight saving time (DST) is observed at Cottonwood Pass 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 at Cottonwood Pass

Sunrise & Sunset with Twilight and Daylight Saving Time at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 135:39 AMJun 135:39 AM8:33 PMJun 278:33 PMJun 27Dec 64:42 PMDec 64:42 PM7:33 AMNov 27:33 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 at Cottonwood Pass

Solar Elevation and Azimuth at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec12 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 AM0001010101020202030303040404050506060700001010102020202030304040505060702875NowNow
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 at Cottonwood Pass

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 at Cottonwood Pass, 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 at Cottonwood Pass

Humidity Comfort Levels at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Jul 20%Jul 20%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 at Cottonwood Pass experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 8.5 months, from October 1 to June 15, with average wind speeds of more than 8.2 miles per hour. The windiest month of the year at Cottonwood Pass is April, with an average hourly wind speed of 10.4 miles per hour.

The calmer time of year lasts for 3.5 months, from June 15 to October 1. The calmest month of the year at Cottonwood Pass is August, with an average hourly wind speed of 5.9 miles per hour.

Average Wind Speed at Cottonwood Pass

Average Wind Speed at Cottonwood PasswindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mph16 mph16 mph18 mph18 mphApr 310.6 mphApr 310.6 mphJul 315.7 mphJul 315.7 mphOct 18.2 mphOct 18.2 mphJun 158.2 mphJun 158.2 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) 10.410.410.310.49.28.06.15.97.38.79.910.4

The predominant average hourly wind direction at Cottonwood Pass is from the west throughout the year.

Wind Direction at Cottonwood Pass

Wind Direction at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestnortheastsouth
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 at Cottonwood Pass 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 Cottonwood Pass for general outdoor tourist activities is from late June to early August, with a peak score in the second week of July.

Tourism Score at Cottonwood Pass

Tourism Score at Cottonwood Passbest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810105.15.10.00.0NowNowtemperaturetemperature 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 Cottonwood Pass for hot-weather activities is from late June to late July, with a peak score in the first week of July.

Beach/Pool Score at Cottonwood Pass

Beach/Pool Score at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec002244668810101.91.90.00.0NowNow 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 at Cottonwood Pass typically lasts for 3.9 months (118 days), from around May 28 to around September 23, rarely starting before May 8 or after June 17, and rarely ending before September 5 or after October 13.

Time Spent in Various Temperature Bands and the Growing Season at Cottonwood Pass

Time Spent in Various Temperature Bands and the Growing Season at Cottonwood Passgrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%May 2850%May 2850%Sep 2350%Sep 2350%Jun 1790%Jun 1790%Sep 590%Sep 590%May 810%May 810%Oct 1310%Oct 1310%0%Feb 270%Feb 27Jul 27100%Jul 27100%NowNowfrigidfreezingvery coldcoldcoolcomfortable
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 at Cottonwood Pass should appear around May 25, only rarely appearing before May 13 or after June 4.

Growing Degree Days at Cottonwood Pass

Growing Degree Days at Cottonwood PassJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F200°F200°F400°F400°F600°F600°F800°F800°F1,000°F1,000°F1,200°F1,200°FMay 2590°FMay 2590°FAug 21900°FAug 21900°FDec 311,188°FDec 311,188°FNowNow
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 2.5 months, from May 9 to July 24, with an average daily incident shortwave energy per square meter above 7.1 kWh. The brightest month of the year at Cottonwood Pass is June, with an average of 8.1 kWh.

The darker period of the year lasts for 3.2 months, from November 1 to February 9, with an average daily incident shortwave energy per square meter below 3.9 kWh. The darkest month of the year at Cottonwood Pass is December, with an average of 2.8 kWh.

Average Daily Incident Shortwave Solar Energy at Cottonwood Pass

Average Daily Incident Shortwave Solar Energy at Cottonwood PassbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWh10 kWh10 kWhJun 138.2 kWhJun 138.2 kWhDec 212.8 kWhDec 212.8 kWhJul 247.1 kWhJul 247.1 kWhNov 13.9 kWhNov 13.9 kWhFeb 93.9 kWhFeb 93.9 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) 3.24.15.46.67.48.17.46.55.84.63.42.8

For the purposes of this report, the geographical coordinates of Cottonwood Pass are 38.783 deg latitude, -106.218 deg longitude, and 9,600 ft elevation.

The topography within 2 miles of Cottonwood Pass contains extreme variations in elevation, with a maximum elevation change of 4,596 feet and an average elevation above sea level of 9,850 feet. Within 10 miles also contains extreme variations in elevation (6,604 feet). Within 50 miles also contains extreme variations in elevation (8,632 feet).

The area within 2 miles of Cottonwood Pass is covered by trees (80%) and shrubs (11%), within 10 miles by trees (36%) and shrubs (32%), and within 50 miles by trees (45%) and shrubs (29%).

This report illustrates the typical weather at Cottonwood Pass, 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

Cottonwood Pass has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.

In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.

The stations on which we may fall back include but are not limited to Harriet Alexander Field Airport; Salida Mountain, Monarch Pass; Lake County Airport; Saguache Municipal Airport; Wilkerson Pass; Copper Mountain, Red Cliff Pass; Gunnison County Airport; and Aspen–Pitkin County Airport.

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.