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2. United States
3. Alaska
4. Anchorage Municipality
5. Birchwood Airport
6. August

Average Weather in August at Birchwood Airport Alaska, United States

Daily high temperatures decrease by 5°F, from 66°F to 61°F, rarely falling below 56°F or exceeding 73°F.

Daily low temperatures decrease by 6°F, from 52°F to 46°F, rarely falling below 40°F or exceeding 55°F.

For reference, on July 13, the hottest day of the year, temperatures at Birchwood Airport typically range from 52°F to 67°F, while on January 20, the coldest day of the year, they range from 10°F to 22°F.

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.

Forsbacka, Sweden (3,707 miles away) is the far-away foreign place with temperatures most similar to Birchwood Airport (view comparison).

The month of August at Birchwood Airport experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 59% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 58% on August 28.

The clearest day of the month is August 28, with clear, mostly clear, or partly cloudy conditions 42% of the time.

For reference, on July 10, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 64%, while on March 16, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 49%.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. At Birchwood Airport, the chance of a wet day over the course of August is essentially constant, remaining around 38% throughout.

For reference, the year's highest daily chance of a wet day is 41% on September 19, and its lowest chance is 14% on March 28.

Rainfall

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 at Birchwood Airport is gradually increasing, starting the month at 2.9 inches, when it rarely exceeds 4.5 inches or falls below 1.4 inches, and ending the month at 3.3 inches, when it rarely exceeds 5.4 inches or falls below 1.6 inches.

The highest average 31-day accumulation is 3.3 inches on August 28.

Over the course of August at Birchwood Airport, 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, 48 minutes, implying an average daily decrease of 5 minutes, 35 seconds, and weekly decrease of 39 minutes, 8 seconds.

The shortest day of the month is August 31, with 14 hours, 22 minutes of daylight and the longest day is August 1, with 17 hours, 9 minutes of daylight.

The earliest sunrise of the month at Birchwood Airport is 5:28 AM on August 1 and the latest sunrise is 1 hour, 18 minutes later at 6:46 AM on August 31.

The latest sunset is 10:38 PM on August 1 and the earliest sunset is 1 hour, 30 minutes earlier at 9:08 PM on August 31.

Daylight saving time is observed at Birchwood Airport during 2019, 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 4:15 AM and sets 19 hours, 28 minutes later, at 11:43 PM, while on December 22, the shortest day of the year, it rises at 10:15 AM and sets 5 hours, 22 minutes later, at 3:37 PM.

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 at Birchwood Airport is essentially constant during August, remaining around 0% throughout.

For reference, on June 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.

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 Birchwood Airport is essentially constant during August, remaining within 0.2 miles per hour of 4.3 miles per hour throughout.

For reference, on January 8, the windiest day of the year, the daily average wind speed is 6.8 miles per hour, while on July 6, the calmest day of the year, the daily average wind speed is 3.9 miles per hour.

Birchwood Airport 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 at Birchwood Airport is essentially constant during August, remaining around 52°F throughout.

The highest average surface water temperature during August is 53°F on August 16.

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 Birchwood Airport typically lasts for 4.7 months (144 days), from around May 2 to around September 23, rarely starting before April 17 or after May 17, and rarely ending before September 4 or after October 9.

The month of August at Birchwood Airport is very likely fully within the growing season, with the chance that a given day is in the growing season gradually decreasing from 100% to 94% over the course of the month.

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 at Birchwood Airport are increasing during August, increasing by 190°F, from 570°F to 760°F, over the course of the month.

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 at Birchwood Airport is decreasing during August, falling by 1.2 kWh, from 4.6 kWh to 3.4 kWh, over the course of the month.

For the purposes of this report, the geographical coordinates of Birchwood Airport are 61.416 deg latitude, -149.509 deg longitude, and 79 ft elevation.

The topography within 2 miles of Birchwood Airport contains only modest variations in elevation, with a maximum elevation change of 440 feet and an average elevation above sea level of 100 feet. Within 10 miles contains only modest variations in elevation (5,302 feet). Within 50 miles also contains extreme variations in elevation (9,846 feet).

The area within 2 miles of Birchwood Airport is covered by trees (31%), water (24%), sparse vegetation (19%), and artificial surfaces (13%), within 10 miles by trees (30%) and shrubs (21%), and within 50 miles by trees (26%) and shrubs (20%).