30-year climate normals

Ketchikan Gateway Borough Climate and Weather Averages

Hottest month — August

64.7°

average daily high. The coldest month is January, averaging a low of 31.5°F.

Ketchikan Gateway Borough gets 149.54" of precipitation a year, and 35% of it falls in Oct, Nov, Dec.

Temperature through the year

Each bar spans the average daily low to the average daily high for that month.

Month	Avg high	Avg low	Precip
January	39.7°	31.5°	16.17"
February	40.9°	31.5°	11.80"
March	43.6°	32.4°	10.98"
April	49.8°	37.2°	10.25"
May	56.9°	43.3°	8.68"
June	61.3°	49.3°	7.02"
July	64.5°	53.2°	7.33"
August	64.7°	53.3°	11.30"
September	58.9°	48.3°	14.30"
October	51.1°	41.3°	18.37"
November	43.7°	35.6°	17.07"
December	40.2°	32.6°	16.27"

Rainfall by month

Precipitation is spread fairly evenly through the year here, with 35% falling in the wettest three months (Oct, Nov, Dec).

January 16.17"

February 11.80"

March 10.98"

April 10.25"

May 8.68"

June 7.02"

July 7.33"

August 11.30"

September 14.30"

October 18.37"

November 17.07"

December 16.27"

Annual total 149.54"

What this climate costs you

Degree days measure how hard a building has to work to stay comfortable. They are the reason two identical houses have very different power bills, and they are the link between the weather here and what you pay every month.

Cooling degree days How much air conditioning the climate demands 16

Heating degree days How much heating the climate demands 6,917

Approximate annual cooling cost At 28.23¢/kWh, Alaska average $5

Approximate annual electric heating cost Lower where heating is gas rather than electric $683

These are rough planning figures from degree days and the state electricity price, not a bill estimate. House size, insulation and fuel type move them a lot. See the full cost of owning a home in Ketchikan Gateway Borough, where electricity is one line of eight.

Common questions

What is the weather like in Ketchikan Gateway Borough?

Ketchikan Gateway Borough averages a high of 64.7°F in August and a low of 31.5°F in January. Annual precipitation is 149.54 inches, with essentially no snow.

When is the rainy season in Ketchikan Gateway Borough?

The wettest stretch is Oct, Nov, Dec, which accounts for 35% of the year's precipitation. Precipitation is relatively evenly distributed across the year.

How hot does it get in Ketchikan Gateway Borough?

The average daily high in August, the hottest month, is 64.7°F. That drives 16 cooling degree days a year, which is what your air conditioning has to work against.

Does it snow in Ketchikan Gateway Borough?

Effectively no. Measurable snowfall is rare in Ketchikan Gateway Borough.

Sources

Temperature, precipitation and snowfall normals — NOAA National Centers for Environmental Information, 1991–2020 Monthly Climate Normals, station KETCHIKAN INTL AP, AK US (USW00025325), 24.6 miles from the county centroid.
Heating and cooling degree days — NOAA, same station and period.
Electricity price — US Energy Information Administration, Electric Power Monthly Table 5.6.A, Alaska residential average.
Wet-season share is the wettest three consecutive months as a percentage of annual precipitation, calculated from the monthly normals.