Climate and Average Weather Year Round at Rock Springs-Sweetwater County Airport Wyoming, United StatesAt Rock Springs-Sweetwater County Airport, the summers are warm, dry, and mostly clear and the winters are freezing, snowy, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 15°F to 84°F and is rarely below -0°F or above 91°F. Based on the tourism score, the best time of year to visit Rock Springs-Sweetwater County Airport for warm-weather activities is from late June to late August. Average Temperature at Rock Springs-Sweetwater County AirportThe warm season lasts for 3.1 months, from June 8 to September 11, with an average daily high temperature above 73°F. The hottest month of the year at Rock Springs-Sweetwater County Airport is July, with an average high of 84°F and low of 56°F. The cold season lasts for 3.5 months, from November 17 to March 2, with an average daily high temperature below 41°F. The coldest month of the year at Rock Springs-Sweetwater County Airport is December, with an average low of 16°F and high of 31°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. Refahiye, Turkey (6,463 miles away) and Brrnakot’, Armenia (6,626 miles) are the far-away foreign places with temperatures most similar to Rock Springs-Sweetwater County Airport (view comparison). CloudsAt Rock Springs-Sweetwater County Airport, 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 at Rock Springs-Sweetwater County Airport begins around June 3 and lasts for 4.5 months, ending around October 18. The clearest month of the year at Rock Springs-Sweetwater County Airport is July, during which on average the sky is clear, mostly clear, or partly cloudy 75% of the time. The cloudier part of the year begins around October 18 and lasts for 7.5 months, ending around June 3. The cloudiest month of the year at Rock Springs-Sweetwater County Airport is March, during which on average the sky is overcast or mostly cloudy 52% of the time.
PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Rock Springs-Sweetwater County Airport varies throughout the year. The wetter season lasts 6.2 months, from April 13 to October 19, with a greater than 10% chance of a given day being a wet day. The month with the most wet days at Rock Springs-Sweetwater County Airport is May, with an average of 4.7 days with at least 0.04 inches of precipitation. The drier season lasts 5.8 months, from October 19 to April 13. The month with the fewest wet days at Rock Springs-Sweetwater County Airport is January, with an average of 1.0 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. Based on this categorization, the most common form of precipitation at Rock Springs-Sweetwater County Airport changes throughout the year. Rain alone is the most common for 9.0 months, from February 20 to November 20. The month with the most days of rain alone at Rock Springs-Sweetwater County Airport is May, with an average of 4.2 days. Snow alone is the most common for 3.0 months, from November 20 to February 20. The month with the most days of snow alone at Rock Springs-Sweetwater County Airport is December, with an average of 0.8 days.
RainfallTo 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. Rock Springs-Sweetwater County Airport experiences some seasonal variation in monthly rainfall. The rainy period of the year lasts for 5.5 months, from April 23 to October 6, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain at Rock Springs-Sweetwater County Airport is May, with an average rainfall of 0.8 inches. The rainless period of the year lasts for 6.6 months, from October 6 to April 23. The month with the least rain at Rock Springs-Sweetwater County Airport is January, with an average rainfall of 0.0 inches.
SnowfallAs with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Rock Springs-Sweetwater County Airport experiences some seasonal variation in monthly snowfall. The snowy period of the year lasts for 5.4 months, from November 3 to April 15, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow at Rock Springs-Sweetwater County Airport is March, with an average snowfall of 1.1 inches. The snowless period of the year lasts for 6.6 months, from April 15 to November 3. The least snow falls around July 19, with an average total accumulation of 0.0 inches.
SunThe length of the day at Rock Springs-Sweetwater County Airport 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.
The earliest sunrise is at 5:41 AM on June 14, and the latest sunrise is 2 hours, 9 minutes later at 7:50 AM on November 2. The earliest sunset is at 4:45 PM on December 7, and the latest sunset is 4 hours, 9 minutes later at 8:54 PM on June 26. Daylight saving time (DST) is observed at Rock Springs-Sweetwater County Airport during 2024, starting in the spring on March 10, lasting 7.8 months, and ending in the fall on November 3. 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. MoonThe 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. HumidityWe 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 Rock Springs-Sweetwater County Airport, 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.
WindThis 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 Rock Springs-Sweetwater County Airport experiences significant seasonal variation over the course of the year. The windier part of the year lasts for 7.4 months, from October 14 to May 28, with average wind speeds of more than 10.1 miles per hour. The windiest month of the year at Rock Springs-Sweetwater County Airport is March, with an average hourly wind speed of 11.9 miles per hour. The calmer time of year lasts for 4.6 months, from May 28 to October 14. The calmest month of the year at Rock Springs-Sweetwater County Airport is August, with an average hourly wind speed of 8.5 miles per hour.
The predominant average hourly wind direction at Rock Springs-Sweetwater County Airport is from the west throughout the year. Best Time of Year to VisitTo characterize how pleasant the weather is at Rock Springs-Sweetwater County Airport 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 Rock Springs-Sweetwater County Airport for general outdoor tourist activities is from late June to late August, with a peak score in the last week of July. Tourism Score at Rock Springs-Sweetwater County AirportThe 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 Rock Springs-Sweetwater County Airport for hot-weather activities is from early July to mid August, with a peak score in the third week of July. Beach/Pool Score at Rock Springs-Sweetwater County AirportMethodologyFor 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 SeasonDefinitions 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 Rock Springs-Sweetwater County Airport typically lasts for 4.4 months (135 days), from around May 15 to around September 28, rarely starting before April 28 or after June 6, and rarely ending before September 10 or after October 19. 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 Rock Springs-Sweetwater County Airport should appear around May 4, only rarely appearing before April 21 or after May 20. Solar EnergyThis 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 3.0 months, from May 12 to August 11, with an average daily incident shortwave energy per square meter above 7.1 kWh. The brightest month of the year at Rock Springs-Sweetwater County Airport is June, with an average of 8.1 kWh. The darker period of the year lasts for 3.5 months, from October 30 to February 13, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest month of the year at Rock Springs-Sweetwater County Airport is December, with an average of 2.2 kWh.
TopographyFor the purposes of this report, the geographical coordinates of Rock Springs-Sweetwater County Airport are 41.594 deg latitude, -109.066 deg longitude, and 6,739 ft elevation. The topography within 2 miles of Rock Springs-Sweetwater County Airport contains only modest variations in elevation, with a maximum elevation change of 472 feet and an average elevation above sea level of 6,547 feet. Within 10 miles contains only modest variations in elevation (2,329 feet). Within 50 miles contains large variations in elevation (4,229 feet). The area within 2 miles of Rock Springs-Sweetwater County Airport is covered by shrubs (100%), within 10 miles by shrubs (99%), and within 50 miles by shrubs (98%). Data SourcesThis report illustrates the typical weather at Rock Springs-Sweetwater County Airport, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointRock Springs-Sweetwater County Airport 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 are Vernal Regional Airport, Hunt Field, Ralph Wenz Field, Big Piney-Marbleton Airport, Rawlins Municipal Airport, and Evanston-Uinta County Burns Field. Other DataAll 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. DisclaimerThe 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. |