September weather forecast
Nikiski, AK

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Weather in September

The first month of the autumn, September, is still a cool month in Nikiski, Alaska, with an average temperature varying between 53.1°F (11.7°C) and 45.7°F (7.6°C).

Temperature

Nikiski's transition into September involves a gentle shift in temperature, receding from a moderate 59.7°F (15.4°C) in August to a fresh 53.1°F (11.7°C). Nikiski registers a subtle dip to an average of 45.7°F (7.6°C) during the nights of September.

Humidity

In Nikiski, the average relative humidity in September is 80%.

Rainfall

In Nikiski, during September, the rain falls for 16.6 days and regularly aggregates up to 2.72" (69mm) of precipitation. In Nikiski, during the entire year, the rain falls for 136.3 days and collects up to 19.49" (495mm) of precipitation.

Snowfall

January through April, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.2" (5mm) of snow. In Nikiski, during the entire year, snow falls for 62.1 days and aggregates up to 30.71" (780mm) of snow.

Daylight

The average length of the day in September is 12h and 50min.
On the first day of September in Nikiski, sunrise is at 7:00 am and sunset at 9:08 pm. On the last day of the month, sunrise is at 8:11 am and sunset at 7:38 pm AKDT.

Sunshine

The average sunshine in September is 6.2h.

UV index

In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: In September, the maximum UV index of 3 translates into these guidelines:
Take necessary precautions - Protection from skin and eye injury is mandatory. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Experience reduced UV exposure by about half when donning a wide-brim hat. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Updated: Jul 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Nikiski, records 53.1°F (11.7°C), while the low-temperature is 45.7°F (7.6°C).

What is the average humidity in September?

The average relative humidity in September in Nikiski is 80%.

How many days does it rain in September?

In Nikiski, during September, the rain falls for 16.6 days and regularly aggregates up to 2.72" (69mm) of precipitation.

When does it start snowing?

September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.2" (5mm) of snow.

How many hours of daylight does Nikiski have in September?

In September, the average day length is 12h and 50min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 7:00 am and sunset at 9:08 pm. On the last day of the month, sunrise is at 8:11 am and sunset at 7:38 pm AKDT.

How many hours of sunshine does Nikiski have in September?

In Nikiski, the average sunshine duration in September is 6.2h.

How high is the UV index in September?

The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Nikiski, AK

Average temperature in September - Nikiski, AK
  • Average high temperature in September: 53.1°F

The warmest month (with the highest average high temperature) is July (61.3°F).
The month with the lowest average high temperature is January (24.3°F).

  • Average low temperature in September: 45.7°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 (18.3°F).

Average pressure in September
Nikiski, AK

Average pressure in September - Nikiski, AK
  • Average pressure in September: 29.73"Hg

The month with the highest atmospheric pressure is July (29.96"Hg).
The month with the lowest atmospheric pressure is December (29.64"Hg).

Average wind speed in September
Nikiski, AK

Average wind speed in September - Nikiski, AK
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is December (9.6mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).

Average humidity in September
Nikiski, AK

Average humidity in September - Nikiski, AK
  • Average humidity in September: 80%

The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is May (69%).

Average rainfall in September
Nikiski, AK

Average rainfall in September - Nikiski, AK
  • Average rainfall in September: 2.72"

The wettest month (with the highest rainfall) is October (2.87").
The driest month (with the least rainfall) is June (0.91").

Average rainfall days in September
Nikiski, AK

Average rainfall days in September - Nikiski, AK
  • Average rainfall days in September: 16.6 days

The month with the highest number of rainy days is September (16.6 days).
The month with the least rainy days is February (5.5 days).

Average snowfall in September
Nikiski, AK

Average snowfall in September - Nikiski, AK
  • Average snowfall in September: 0.2"

The month with the highest snowfall is December (8.74").
The months with the least snowfall are May, June, July and August (0").

Average snowfall days in September
Nikiski, AK

Average snowfall days in September - Nikiski, AK
  • Average snowfall days in September: 0.3 days

The month with the highest number of snowfall days is December (12.7 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Nikiski, AK

Average daylight in September / Average sunshine in September - Nikiski, AK
  • Average daylight in September: 12h and 5min

The month with the longest days is June (Average daylight: 19h and 0min).
The month with the shortest days is December (Average daylight: 5h and 48min).

  • Average sunshine in September: 6h and 1min

The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 2h and 54min).

Average sunshine days in September
Nikiski, AK

Average sunshine days in September - Nikiski, AK
  • Average sunshine days in September: 11.5 days

The month with the most sunshine days is June (16.6 days).
The month with the least sunshine days is September (11.5 days).

Average UV index in September
Nikiski, AK

Average UV index in September - Nikiski, AK
  • Average UV index in September: 3

The months with the highest UV index are June and July (UV index 4).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Nikiski, AK

Average cloud cover in September - Nikiski, AK
  • Average cloud cover in September: 51

The month with the most cloud cover is December (Cloud cover 58).
The month with the least cloud cover is June (Cloud cover 44).

Average visibility in September
Nikiski, AK

Average visibility in September - Nikiski, AK
  • Average visibility in September: 6mi

The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is February (5mi).

Nikiski, Alaska, USA

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