Friday Harbor weather by month
What a typical year looks like in Friday Harbor, Washington: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Friday Harbor Airport, 2 km from Friday Harbor; records cover 1998–2026.
The year at a glance
- Precipitation a year
- 18.5 in469 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 9
- First fall freeze
- Nov 4
- Heating degree days
- 5,170
- Cooling degree days
- 32
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 23°−5° (heating, 99%) and 84°29° (cooling, 1%).
Month by month
Friday Harbor in January
Highs average 47°8° and lows 37°3°, with 2.7 in68 mm of precipitation in a typical January.
- Record high
- 62°17° (2024)
- Record low
- 10°−12° (2024)
- Heating degree days
- 710
- Cooling degree days
- 0
Friday Harbor in February
Highs average 49°9° and lows 37°3°, with 1.5 in39 mm of precipitation in a typical February.
- Record high
- 71°22° (2025)
- Record low
- 17°−8° (2011)
- Heating degree days
- 630
- Cooling degree days
- 0
Friday Harbor in March
Highs average 53°11° and lows 38°4°, with 1.4 in34 mm of precipitation in a typical March.
- Record high
- 76°24° (2024)
- Record low
- 19°−7° (2009)
- Heating degree days
- 604
- Cooling degree days
- 0
Friday Harbor in April
Highs average 57°14° and lows 41°5°, with 1 in26 mm of precipitation in a typical April.
- Record high
- 81°27° (2025)
- Record low
- 27°−3° (2008)
- Heating degree days
- 478
- Cooling degree days
- 0
Friday Harbor in May
Highs average 64°18° and lows 44°7°, with 1.1 in29 mm of precipitation in a typical May.
- Record high
- 89°32° (2023)
- Record low
- 30°−1° (2002)
- Heating degree days
- 341
- Cooling degree days
- 0
Friday Harbor in June
Highs average 68°20° and lows 48°9°, with 0.75 in19 mm of precipitation in a typical June.
- Record high
- 101°38° (2021)
- Record low
- 36°2° (1999)
- Heating degree days
- 207
- Cooling degree days
- 5
Friday Harbor in July
Highs average 72°22° and lows 50°10°, with 0.48 in12 mm of precipitation in a typical July.
- Record high
- 97°36° (2009)
- Record low
- 40°4° (2000)
- Heating degree days
- 130
- Cooling degree days
- 12
Friday Harbor in August
Highs average 73°23° and lows 50°10°, with 0.7 in18 mm of precipitation in a typical August.
- Record high
- 93°34° (2016)
- Record low
- 42°6° (2000)
- Heating degree days
- 116
- Cooling degree days
- 12
Friday Harbor in September
Highs average 68°20° and lows 48°9°, with 1 in26 mm of precipitation in a typical September.
- Record high
- 89°32° (2017)
- Record low
- 36°2° (2000)
- Heating degree days
- 213
- Cooling degree days
- 3
Friday Harbor in OctoberThis month
Highs average 59°15° and lows 44°7°, with 2.3 in59 mm of precipitation in a typical October.
- Record high
- 78°26° (2023)
- Record low
- 26°−3° (2002)
- Heating degree days
- 426
- Cooling degree days
- 0
Friday Harbor in November
Highs average 51°11° and lows 40°4°, with 3 in76 mm of precipitation in a typical November.
- Record high
- 66°19° (2016)
- Record low
- 12°−11° (2010)
- Heating degree days
- 588
- Cooling degree days
- 0
Friday Harbor in December
Highs average 46°8° and lows 37°3°, with 2.5 in62 mm of precipitation in a typical December.
- Record high
- 59°15° (2023)
- Record low
- 8°−13° (2008)
- Heating degree days
- 727
- Cooling degree days
- 0