September weather forecast and climate
Koyuk, AK

Weather in September

The first month of the autumn, September, is still a chilly month in Koyuk, Alaska, with average temperature varying between 48.9°F (9.4°C) and 40.3°F (4.6°C).

Temperature

In Koyuk, Alaska, the average high-temperature marginally drops, from a moderate 57.2°F (14°C) in August, to a chilly 48.9°F (9.4°C). The average low-temperature, in Koyuk, is 40.3°F (4.6°C).

Humidity

The average relative humidity in Koyuk is 80%.

Rainfall

In Koyuk, during 15.1 rainfall days, 1.42" (36mm) of precipitation is typically accumulated. In Koyuk, Alaska, during the entire year, the rain falls for 118.6 days and collects up to 13.39" (340mm) of precipitation.

Snowfall

Months with snowfall in Koyuk are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 1.4 snowfall days, it receives 0.16" (4mm) of snow. In Koyuk, during the entire year, snow falls for 94.3 days, and aggregates up to 27.2" (691mm) of snow.

Daylight

In September, the average length of the day in Koyuk is 13h.

Sunshine

In September, the average sunshine is 5.3h.

UV index

The average daily maximum UV index in Koyuk is 2. A UV Index of 2, and less, symbolizes a low threat to health from unprotected exposure to the Sun's UV rays for average individuals.
Note: In September, the average maximum UV index of 2 translate into the following recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
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FAQ

What is the temperature in September in Koyuk?

In September, in Koyuk, Alaska, the average high-temperature is 48.9°F (9.4°C), and the average low-temperature is 40.3°F (4.6°C).

What is the average humidity in September in Koyuk?

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

How much does it rain in Koyuk in September?

In Koyuk, Alaska, in September, it is raining for 15.1 days, with typically 1.42" (36mm) of accumulated precipitation.

When does it start to snow in Koyuk?

September is the first month it typically snows in Koyuk, Alaska. Throughout September, in the average 1.4 snowfall days, it receives 0.16" (4mm) of snow.

How many hours of daylight does Koyuk have in September?

In Koyuk, Alaska, the average length of the day in September is 13h.

How long on average sun shines in September in Koyuk?

The average sunshine in September in Koyuk, Alaska, is 5.3h.

What is the UV index intensity in September in Koyuk?

In September, the average daily maximum UV index in Koyuk is 2. A UV Index of 2, and less, symbolizes a low health risk from the exposure to the Sun's UV rays.

Average temperature in September
Koyuk, AK

Average temperature in September - Koyuk, AK
  • Average high temperature in September: 48.9°F

The warmest month (with the highest average high temperature) is July (59.5°F).
The month with the lowest average high temperature is January (9.1°F).

  • Average low temperature in September: 40.3°F

The month with the highest average low temperature is July (48.7°F).
The coldest month (with the lowest average low temperature) is January (1.8°F).

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Average pressure in September
Koyuk, AK

Average pressure in September - Koyuk, AK
  • Average pressure in September: 29.75"

The month with the highest atmospheric pressure is May (29.92").
The month with the lowest atmospheric pressure is October (29.72").

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Average wind speed in September
Koyuk, AK

Average wind speed in September - Koyuk, AK
  • Average wind speed in September: 8.5mph

The windiest month (with the highest average wind speed) is October (9.6mph).
The calmest month (with the lowest average wind speed) is June (6mph).

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Average humidity in September
Koyuk, AK

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

The month with the highest relative humidity is March (92%).
The month with the lowest relative humidity is June (72%).

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Average rainfall in September
Koyuk, AK

Average rainfall in September - Koyuk, AK
  • Average rainfall in September: 1.42"

The wettest month (with the highest rainfall) is August (2.24").
The driest month (with the least rainfall) is January (0.55").

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Average rainfall days in September
Koyuk, AK

Average rainfall days in September - Koyuk, AK
  • Average rainfall days in September: 15.1 days

The month with the highest number of rainy days is August (19.8 days).
The month with the least rainy days is January (2.7 days).

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Average snowfall in September
Koyuk, AK

Average snowfall in September - Koyuk, AK
  • Average snowfall in September: 0.16"

The month with the highest snowfall is November (4.76").
Months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Koyuk, AK

Average snowfall days in September - Koyuk, AK
  • Average snowfall days in September: 1.4 days

The month with the highest number of snowfall days is March (16.7 days).
Months with the least snowfall days are June, July and August (0 days).

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

Average daylight in September / Average sunshine in September - Koyuk, AK
  • Average daylight in September: 13h

The month with the longest days is June (Average daylight: 21.6h).
The month with the shortest days is December (Average daylight: 3.9h).

  • Average sunshine in September: 5.3h

The month with the most sunshine is May (Average sunshine: 8.3h).
The month with the least sunshine is June (Average sunshine: 2.9h).

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Average sunshine days in September
Koyuk, AK

Average sunshine days in September - Koyuk, AK
  • Average sunshine days in September: 12.5 days

The month with the most sunshine days is January (18.3 days).
The month with the least sunshine days is August (8.4 days).

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Average UV index in September
Koyuk, AK

Average UV index in September - Koyuk, AK
  • Average UV index in September: 2

The month with the highest UV index is July (UV index 4).
Months with the lowest UV index are January, February, March and December (UV index 1).

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Average cloud cover in September
Koyuk, AK

Average cloud cover in September - Koyuk, AK
  • Average cloud cover in September: 58

The month with the most cloud cover is August (Cloud cover 62).
The month with the least cloud cover is June (Cloud cover 50).

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Average visibility in September
Koyuk, AK

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

Months with the highest visibility are May, June, July, August, September and October (6mi).
Months with the lowest visibility are January, February, March, April and December (4mi).

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