September weather forecastAnchorage, AK
September
Weather in September
September marks the beginning of fall in Anchorage, as temperatures drop from August highs and daylight hours drastically shorten. Despite the melancholy of shrinking days, the city is ablaze with the vibrant colors of autumn foliage. Rainfall peaks at 1.93" (49mm) this month, the highest for the year, breathing a sprightly vigor into the natural surroundings. Wind strength remains steady, adding a crisp breeze to the somewhat cooler climate. With the capture of such an array of color and mood, Anchorage in September is a photographer's delight.Temperature
Anchorage, Alaska, records a mild change in average high-temperature during September, easing from a refreshing 59.5°F (15.3°C) in August to a fresh 52.7°F (11.5°C). Anchorage marks an average drop to a frosty 43.9°F (6.6°C) during nighttime in September, following the high of the day.Humidity
The average relative humidity in September is 78%.Rainfall
The month with the most rainfall is September, when the rain falls for 16 days and typically aggregates up to 1.93" (49mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Anchorage. Throughout September, in the average 0.3 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 59.3 snowfall days, and 23.5" (597mm) of snow is accumulated.Ocean temperature
In Anchorage, the average seawater temperature in September is 51.6°F (10.9°C).Note: It is life-risking to swim in 51.6°F (10.9°C). Briefly staying in 55.4°F (13°C) waters feels unsettling, and temperatures below 50°F (10°C) might result in cold shock and loss of breath control, hinging on personal endurance.
Daylight
In September, the average length of the day is 12h and 52min.On the first day of the month, sunrise is at 6:53 am and sunset at 9:04 pm. On the last day of September, sunrise is at 8:06 am and sunset at 7:32 pm AKDT.
Sunshine
The average sunshine in September is 7.6h.UV index
In Anchorage, the average daily maximum UV index in September is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: A maximum daily UV index of 2 during September morphs into the following directions:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Boost your sun resistance with garments that are densely woven yet spacious. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Anchorage, AK
- Average high temperature in September: 52.7°F
The warmest month (with the highest average high temperature) is July (61.9°F).
The month with the lowest average high temperature is January (20.3°F).
- Average low temperature in September: 43.9°F
The month with the highest average low temperature is July (51.3°F).
The coldest month (with the lowest average low temperature) is January (13.1°F).
Average pressure in September
Anchorage, AK
- Average pressure in September: 29.74"Hg
The month with the highest atmospheric pressure is July (29.96"Hg).
The months with the lowest atmospheric pressure are November and December (29.67"Hg).
Average wind speed in September
Anchorage, AK
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is November (6.3mph).
The calmest month (with the lowest average wind speed) is July (4.5mph).
Average humidity in September
Anchorage, AK
- Average humidity in September: 78%
The months with the highest relative humidity are January, February and March (86%).
The month with the lowest relative humidity is May (68%).
Average rainfall in September
Anchorage, AK
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is September (1.93").
The driest month (with the least rainfall) is May (0.55").
Average rainfall days in September
Anchorage, AK
- Average rainfall days in September: 16 days
The month with the highest number of rainy days is August (17.9 days).
The month with the least rainy days is February (7 days).
Average snowfall in September
Anchorage, AK
- Average snowfall in September: 0.08"
The month with the highest snowfall is December (5.51").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Anchorage, AK
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (11.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average sea temperature in September
Anchorage, AK
- Average sea temperature in September: 51.6°F
The best month for swimming (with the highest average sea temperature) is August (53.1°F).
The coldest month (with the lowest average sea temperature) is February (35.8°F).
Average daylight in September /
Average sunshine in September
Anchorage, AK
- Average daylight in September: 12h and 54min
The month with the longest days is June (Average daylight: 19h and 12min).
The month with the shortest days is December (Average daylight: 5h and 36min).
- Average sunshine in September: 7h and 36min
The months with the most sunshine are May and June (Average sunshine: 11h and 42min).
The month with the least sunshine is December (Average sunshine: 3h and 48min).
Average sunshine days in September
Anchorage, AK
- Average sunshine days in September: 11.1 days
The month with the most sunshine days is January (16.9 days).
The month with the least sunshine days is September (11.1 days).
Average UV index in September
Anchorage, AK
- Average UV index in September: 2
The months with the highest UV index are June and July (UV index 4).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Anchorage, AK
- Average cloud cover in September: 44
The month with the most cloud cover is December (Cloud cover 47).
The month with the least cloud cover is May (Cloud cover 38).
Average visibility in September
Anchorage, AK
- Average visibility in September: 6mi
The months with the highest visibility are January, February, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is March (5mi).
