September weather forecast and climate
Ketchikan, AK

Beautiful and colorful houses along the waterfront boardwalk on Creek Street in Ketchikan, Alaska
Beautiful and colorful houses along the waterfront boardwalk on Creek Street in Ketchikan, Alaska

Weather in September

September, the first month of the autumn, in Ketchikan, is still a mild month, with temperature in the range of an average high of 56.3°F (13.5°C) and an average low of 48.7°F (9.3°C).

Temperature

In September, the average high-temperature is practically the same as in August - a mild 56.3°F (13.5°C). The average low-temperature, in September, is 48.7°F (9.3°C).

Humidity

The average relative humidity in Ketchikan is 86%.

Rainfall

In Ketchikan, during September, the rain falls for 19.3 days and regularly aggregates up to 6.85" (174mm) of precipitation. Throughout the year, there are 221.8 rainfall days, and 80" (2032mm) of precipitation is accumulated.

Snowfall

June through October are months without snowfall.

Ocean temperature

In Ketchikan, the average water temperature is 53.2°F (11.8°C).
Note: Swimming in 53.2°F (11.8°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

The average length of the day in September is 12.7h.

Sunshine

The average sunshine in September is 6.3h.

UV index

The average daily maximum UV index in Ketchikan is 3. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to the UV radiation for average individuals.
Note: The daily maximum UV index of 3 interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the temperature in September in Ketchikan?

The average high-temperature, in September, is 56.3°F (13.5°C), while the average low-temperature is 48.7°F (9.3°C).

What is the average humidity in September in Ketchikan?

In Ketchikan, Alaska, the average relative humidity in September is 86%.

How much does it rain in Ketchikan in September?

In Ketchikan, during September, the rain falls for 19.3 days and regularly aggregates up to 6.85" (174mm) of precipitation.

When it does not snow in Ketchikan?

June through October are months without snowfall.

What is the water temperature in September in Ketchikan?

In Ketchikan, Alaska, the average seawater temperature in September is 53.2°F (11.8°C). Swimming in 53.2°F (11.8°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in September in Ketchikan?

In September, the average length of the day in Ketchikan, Alaska, is 12.7h.

How long on average sun shines in September in Ketchikan?

In Ketchikan, the average sunshine in September is 6.3h.

What is the UV index intensity in September in Ketchikan?

The average daily maximum UV index in September in Ketchikan is 3. A UV Index estimate of 3 to 5 represents a moderate health threat from the exposure to the Sun's UV radiation.

Average temperature in September
Ketchikan, AK

Average temperature in September - Ketchikan, AK
  • Average high temperature in September: 56.3°F

The warmest months (with the highest average high temperature) are July and August (60.8°F).
The month with the lowest average high temperature is December (35.8°F).

  • Average low temperature in September: 48.7°F

The month with the highest average low temperature is August (52°F).
The coldest month (with the lowest average low temperature) is February (30.6°F).

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Average pressure in September
Ketchikan, AK

Average pressure in September - Ketchikan, AK
  • Average pressure in September: 29.93"

The month with the highest atmospheric pressure is July (30.06").
The month with the lowest atmospheric pressure is November (29.8").

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Average wind speed in September
Ketchikan, AK

Average wind speed in September - Ketchikan, AK
  • Average wind speed in September: 6.2mph

The windiest month (with the highest average wind speed) is January (8.7mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).

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Average humidity in September
Ketchikan, AK

Average humidity in September - Ketchikan, AK
  • Average humidity in September: 86%

The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is May (82%).

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Average rainfall in September
Ketchikan, AK

Average rainfall in September - Ketchikan, AK
  • Average rainfall in September: 6.85"

The wettest month (with the highest rainfall) is January (9.69").
The driest month (with the least rainfall) is May (3.46").

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Average rainfall days in September
Ketchikan, AK

Average rainfall days in September - Ketchikan, AK
  • Average rainfall days in September: 19.3 days

The month with the highest number of rainy days is November (21.4 days).
The month with the least rainy days is February (14.2 days).

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Average snowfall in September
Ketchikan, AK

Average snowfall in September - Ketchikan, AK
  • Average snowfall in September: 0"

The month with the highest snowfall is February (13.11").
Months with the least snowfall are June, July, August, September and October (0").

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Average snowfall days in September
Ketchikan, AK

Average snowfall days in September - Ketchikan, AK
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is March (10.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

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Average sea temperature in September
Ketchikan, AK

Average sea temperature in September - Ketchikan, AK
  • Average sea temperature in September: 53.3°F

The best month for swimming (with the highest average sea temperature) is August (55.9°F).
The coldest month (with the lowest average sea temperature) is March (42.5°F).

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

Average daylight in September / Average sunshine in September - Ketchikan, AK
  • Average daylight in September: 12.7h

The month with the longest days is June (Average daylight: 17.4h).
The month with the shortest days is December (Average daylight: 7.2h).

  • Average sunshine in September: 6.3h

The month with the most sunshine is May (Average sunshine: 7.2h).
The month with the least sunshine is January (Average sunshine: 3h).

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Average sunshine days in September
Ketchikan, AK

Average sunshine days in September - Ketchikan, AK
  • Average sunshine days in September: 9.9 days

The month with the most sunshine days is July (11.9 days).
The month with the least sunshine days is November (5.6 days).

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Average UV index in September
Ketchikan, AK

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

Months with the highest UV index are July and August (UV index 4).
Months with the lowest UV index are January, November and December (UV index 1).

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Average cloud cover in September
Ketchikan, AK

Average cloud cover in September - Ketchikan, AK
  • Average cloud cover in September: 56

The month with the most cloud cover is January (Cloud cover 71).
The month with the least cloud cover is May (Cloud cover 55).

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Average visibility in September
Ketchikan, AK

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

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

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