August Weather in Gillette Wyoming, United States
Daily high temperatures decrease by 5°F, from 87°F to 81°F, rarely falling below 68°F or exceeding 95°F.
Daily low temperatures decrease by 5°F, from 58°F to 52°F, rarely falling below 43°F or exceeding 65°F.
For reference, on July 27, the hottest day of the year, temperatures in Gillette typically range from 58°F to 87°F, while on December 29, the coldest day of the year, they range from 14°F to 33°F.
Average High and Low Temperature in August in Gillette
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. The horizontal axis is the day, 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 August in Gillette
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 month of August in Gillette experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 26% throughout the month.
The clearest day of the month is August 10, with clear, mostly clear, or partly cloudy conditions 76% of the time.
For reference, on March 20, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 55%, while on July 4, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 77%.
Cloud Cover Categories in August in Gillette
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Gillette, the chance of a wet day over the course of August is decreasing, starting the month at 18% and ending it at 12%.
For reference, the year's highest daily chance of a wet day is 31% on June 2, and its lowest chance is 3% on January 15.
Probability of Precipitation in August in Gillette
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during August in Gillette is essentially constant, remaining about 0.8 inches throughout, and rarely exceeding 1.9 inches or falling below 0.1 inches.
The lowest average 31-day accumulation is 0.7 inches on August 26.
Average Monthly Rainfall in August in Gillette
Over the course of August in Gillette, the length of the day is rapidly decreasing. From the start to the end of the month, the length of the day decreases by 1 hour, 21 minutes, implying an average daily decrease of 2 minutes, 42 seconds, and weekly decrease of 18 minutes, 57 seconds.
The shortest day of the month is August 31, with 13 hours, 15 minutes of daylight and the longest day is August 1, with 14 hours, 36 minutes of daylight.
Hours of Daylight and Twilight in August in Gillette
The earliest sunrise of the month in Gillette is 5:49 AM on August 1 and the latest sunrise is 34 minutes later at 6:24 AM on August 31.
The latest sunset is 8:26 PM on August 1 and the earliest sunset is 47 minutes earlier at 7:39 PM on August 31.
Daylight saving time is observed in Gillette during 2021, but it neither starts nor ends during August, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:18 AM and sets 15 hours, 32 minutes later, at 8:49 PM, while on December 21, the shortest day of the year, it rises at 7:34 AM and sets 8 hours, 51 minutes later, at 4:25 PM.
Sunrise & Sunset with Twilight in August in Gillette
The figure below presents a compact representation of key lunar data for August 2021. 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in August in Gillette
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 chance that a given day will be muggy in Gillette is essentially constant during August, remaining around 0% throughout.
For reference, on July 15, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in August in Gillette
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Gillette is gradually increasing during August, increasing from 8.8 miles per hour to 9.5 miles per hour over the course of the month.
For reference, on January 17, the windiest day of the year, the daily average wind speed is 11.4 miles per hour, while on July 26, the calmest day of the year, the daily average wind speed is 8.8 miles per hour.
Average Wind Speed in August in Gillette
The hourly average wind direction in Gillette throughout August is predominantly from the south, with a peak proportion of 35% on August 18.
Wind Direction in August in Gillette
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 Gillette typically lasts for 4.4 months (137 days), from around May 15 to around September 29, rarely starting before April 29 or after June 1, and rarely ending before September 10 or after October 16.
The month of August in Gillette is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in August in Gillette
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.
The average accumulated growing degree days in Gillette are rapidly increasing during August, increasing by 566°F, from 1,340°F to 1,906°F, over the course of the month.
Growing Degree Days in August in Gillette
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 in Gillette is decreasing during August, falling by 1.1 kWh, from 7.2 kWh to 6.1 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in August in Gillette
For the purposes of this report, the geographical coordinates of Gillette are 44.291 deg latitude, -105.502 deg longitude, and 4,557 ft elevation.
The topography within 2 miles of Gillette contains only modest variations in elevation, with a maximum elevation change of 371 feet and an average elevation above sea level of 4,569 feet. Within 10 miles contains only modest variations in elevation (978 feet). Within 50 miles contains very significant variations in elevation (2,736 feet).
The area within 2 miles of Gillette is covered by grassland (51%), shrubs (36%), and artificial surfaces (11%), within 10 miles by grassland (92%), and within 50 miles by grassland (85%) and shrubs (14%).
This report illustrates the typical weather in Gillette, 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 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Gillette.
For each station, the records are corrected for the elevation difference between that station and Gillette 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 Gillette is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Gillette and a given station.
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 © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
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.