Average Weather in August in Anchorage Alaska, United States
In Anchorage, the month of August is characterized by falling daily high temperatures, with daily highs decreasing by 5°F, from 67°F to 62°F over the course of the month, and rarely exceeding 74°F or dropping below 57°F.
Daily low temperatures decrease by 6°F, from 55°F to 49°F, rarely falling below 43°F or exceeding 59°F.
For reference, on July 20, the hottest day of the year, temperatures in Anchorage typically range from 55°F to 68°F, while on January 17, the coldest day of the year, they range from 13°F to 23°F.
Average High and Low Temperature in August
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
The month of August in Anchorage experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 58% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 57% on August 28.
The clearest day of the month is August 28, with clear, mostly clear, or partly cloudy conditions 43% of the time.
For reference, on December 18, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 63%, while on March 16, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 48%.
Cloud Cover in August
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Anchorage, the chance of a wet day over the course of August is gradually increasing, starting the month at 33% and ending it at 35%.
For reference, the year's highest daily chance of a wet day is 39% on September 27, and its lowest chance is 13% on March 28.
Probability of Precipitation in August
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 Anchorage is gradually increasing, starting the month at 2.7 inches, when it rarely exceeds 4.3 inches or falls below 1.2 inches, and ending the month at 3.1 inches, when it rarely exceeds 5.0 inches or falls below 1.5 inches.
Average Monthly Rainfall in August
Over the course of August in Anchorage, the length of the day is very rapidly decreasing. From the start to the end of the month, the length of the day decreases by 2 hours, 46 minutes, implying an average daily decrease of 5 minutes, 32 seconds, and weekly decrease of 38 minutes, 45 seconds.
The shortest day of the month is August 31, with 14 hours, 18 minutes of daylight and the longest day is August 1, with 17 hours, 4 minutes of daylight.
Hours of Daylight and Twilight in August
The earliest sunrise of the month in Anchorage is 5:33 AM on August 1 and the latest sunrise is 1 hour, 17 minutes later at 6:49 AM on August 31.
The latest sunset is 10:36 PM on August 1 and the earliest sunset is 1 hour, 29 minutes earlier at 9:07 PM on August 31.
Daylight saving time is observed in Anchorage during 2017, 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 4:20 AM and sets 19 hours, 23 minutes later, at 11:42 PM, while on December 21, the shortest day of the year, it rises at 10:14 AM and sets 5 hours, 27 minutes later, at 3:41 PM.
Sunrise & Sunset with Twilight in August
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 Anchorage is essentially constant during August, remaining around 0% throughout.
For reference, on June 19, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the leasy muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in August
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 Anchorage is essentially constant during August, remaining within 0.1 miles per hour of 2.5 miles per hour throughout.
For reference, on January 8, the windiest day of the year, the daily average wind speed is 3.5 miles per hour, while on July 6, the calmest day of the year, the daily average wind speed is 2.3 miles per hour.
Average Wind Speed in August
Wind Direction in August
Anchorage is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Anchorage is essentially constant during August, remaining around 54°F throughout.
The highest average surface water temperature during August is 55°F on August 15.
Average Water Temperature in August
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 Anchorage is decreasing during August, falling by 1.3 kWh, from 4.7 kWh to 3.4 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in August
For the purposes of this report, the geographical coordinates of Anchorage are 61.218 deg latitude, -149.900 deg longitude, and 69 ft elevation.
The topography within 2 miles of Anchorage contains only modest variations in elevation, with a maximum elevation change of 177 feet and an average elevation above sea level of 48 feet. Within 10 miles contains only modest variations in elevation (3,212 feet). Within 50 miles contains large variations in elevation (7,936 feet).
The area within 2 miles of Anchorage is covered by artificial surfaces (79%) and sparse vegetation (14%), within 10 miles by water (29%) and trees (22%), and within 50 miles by trees (32%) and shrubs (21%).
This report illustrates the typical weather in Anchorage year round, 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 Anchorage.
For each station, the records are corrected for the elevation difference between that station and Anchorage 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 Anchorage is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Anchorage 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 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.