Friday Harbor, WA Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Friday Harbor's primary NOAA station, FRIDAY HARBOR AP.
The climate verdict for Friday Harbor
Dryness leads the climate profile for Friday Harbor, Washington, with 18.5 inches of precipitation a year. NOAA records an annual average of 51°F. Its climate comfort score of 56/100 (moderate) lands mid-pack nationally, exceeding 36% of station-mapped location scores.
- 51°F
- average temperature, NOAA 1991-2020 normal
- 56/100
- comfort score, above 36% of station-mapped location scores
- 18.5"
- annual precipitation
- 229 days
- frost-free growing season
Friday Harbor: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00094276 · Friday Harbor, WA 51°F mean · 18.5" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-DRY · SWING-NARROW · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 51°F
- RANK-MID #3,019
- PHOTO-FINISH ≈ Orick Prairie C…
- PRCP-DRY 18.5"
- SWING-NARROW 20°F
- COMF-MID 56/100
- LOAD-HEAT 5,171 HDD
- STN-1 USW00094276
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Orick Prairie Creek Park, CA (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every WA station list.
- Friday Harbor (this station) 51°F
- Cold Olga, WA 51°F
- Hot Honeyman State…, OR 51°F
- Near Orick Prairie C…, CA 51°F
- Near Grayland, WA 51°F
Climate Living Index · Friday Harbor
Friday Harbor: 67/100 · grade C
Friday Harbor publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Friday Harbor, not an official NOAA rating. Rankings still use Comfort Score 56/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Frost-free season | 229 days/year | 81/100 · B |
| Annual temperature balance | 50.9°F · 16.6° from 67.5°F | 44/100 · D |
| Precipitation balance | 18.5 in · 16.5 from 35 in | 41/100 · D |
Friday Harbor · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Friday Harbor is a temperate Köppen climate: Csb
Coldest-month mean 41.6°F and warmest-month mean 61.6°F place this station in temperate, dry-summer, warm summer climates (Csb). Class Csb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, dry-summer, warm summer.
- Köppen code
- Csb
- Group
- Temperate
- Warmest month
- 61.6°F
- Coldest month
- 41.6°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Friday Harbor sits across the climate record
Three NOAA fields for Friday Harbor's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 44th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Drier than 75%
- Friday Harbor's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 97%
- Warmest-to-coldest month gap for Friday Harbor is compact versus 6,861 complete station-years.
How Friday Harbor compares across U.S. station-mapped locations
Friday Harbor's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
56 36th percentile score exceeds 36% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). This entry sits in this band.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 47°F (8°C) | 37°F (3°C) | 42°F (6°C) | 2.7" | 8.1 | 0.0 |
| February | 49°F (9°C) | 37°F (3°C) | 43°F (6°C) | 1.5" | 9.0 | 0.0 |
| March | 53°F (11°C) | 38°F (4°C) | 46°F (8°C) | 1.4" | 5.9 | 0.0 |
| April | 57°F (14°C) | 41°F (5°C) | 49°F (10°C) | 1.0" | 2.4 | 0.0 |
| May | 64°F (18°C) | 44°F (7°C) | 54°F (12°C) | 1.1" | 0.3 | 0.0 |
| June | 68°F (20°C) | 48°F (9°C) | 58°F (15°C) | 0.8" | 0.0 | 0.0 |
| July | 72°F (22°C) | 50°F (10°C) | 61°F (16°C) | 0.5" | 0.0 | 0.3 |
| August | 73°F (23°C) | 50°F (10°C) | 62°F (16°C) | 0.7" | 0.0 | 0.2 |
| September | 68°F (20°C) | 48°F (9°C) | 58°F (14°C) | 1.0" | 0.0 | 0.0 |
| October | 59°F (15°C) | 44°F (7°C) | 51°F (11°C) | 2.3" | 0.6 | 0.0 |
| November | 51°F (11°C) | 40°F (4°C) | 45°F (7°C) | 3.0" | 5.1 | 0.0 |
| December | 46°F (8°C) | 37°F (3°C) | 42°F (5°C) | 2.5" | 8.8 | 0.0 |
The year, day by day
The calendar barely moves in Friday Harbor: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 36°F near February 13 and 74°F near August 1.
No freezing date
Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 36°F around February 13.
Where the wet dates fall
The likeliest wet date is November 7, when 55% of years recorded at least a hundredth of an inch. The driest is July 22 at 18%. Summed across the calendar, that is about 145 wet dates a year.
The widest day
August 9 carries the biggest normal gap between afternoon and dawn, 24°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Friday Harbor.
Monthly Precipitation
Average monthly rainfall
16.7 days with precipitation
13.8 days with precipitation
14.3 days with precipitation
10.3 days with precipitation
9.6 days with precipitation
7.5 days with precipitation
5.0 days with precipitation
7.7 days with precipitation
11.8 days with precipitation
15.2 days with precipitation
16.3 days with precipitation
15.9 days with precipitation
Friday Harbor's wet season runs through the cold months
December, January and February carry 36% of the year's precipitation here, while June through August contribute 10%. That is the cool-season-dominant pattern of the West Coast and the higher inland West, where storm tracks swing south in winter and summer turns dry; the thermometer meanwhile shows an unusually narrow 20°F seasonal spread.
- Wettest month
- November, 3.0"
- Driest month
- July, 0.5"
- Wettest three months
- November, January, December (44% of the year)
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A cool-season label means the December-February share reaches 35%. Where snow falls, the monthly figures above report liquid-equivalent precipitation, so a wet winter month is not necessarily a rainy one.
Rain reaches Friday Harbor in small, frequent amounts
Friday Harbor records about 144 days with measurable precipitation a year and 18.5" in total, which works out to roughly 0.13 inches on an average wet day. Precipitation on 39% of all days, arriving that lightly, is the damp many-grey-days pattern rather than the storm-driven one.
Places in this band read as wetter than their annual totals suggest, because what people notice is the number of overcast days, not the depth in the gauge.
- Most wet days: January, about 17 of them.
- Fewest: July, about 5.
- Average depth per wet day: 0.13 inches.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Frost Dates & Growing Season
First Fall Freeze
November 10
50% probability date
Last Spring Freeze
March 26
50% probability date
Growing Season
229 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
5,171
Higher = more heating needed
Cooling Degree Days
32
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside WA closest to Friday Harbor on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (51°F here).
- Belington, WV 51°F · 0.0°F off
- Bland, VA 51°F · 0.0°F off
- Des Moines, IA 51°F · 0.0°F off
- Falls City, OR 51°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (18.5" here), excluding temperature-peer places.
- Flasher, ND 18.5" · 0.0" off
- Glenbrook, NV 18.5" · 0.0" off
- Canyon, TX 18.4" · 0.0" off
- Tooele, UT 18.4" · 0.0" off
Data-derived climate profile
How Friday Harbor's climate pattern fits together
heating led · dry · low swing
Heating is the larger measured load in Friday Harbor, at 5,171 degree days versus 32 for cooling. Unlike a strongly continental record, however, its 20.0°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
Friday Harbor's frost-free season lasts about 229 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
The calendar stays thermally compact and dry. August and December mark the typical warm and cold ends of the calendar, only 20.0°F apart, while the annual precipitation total remains below PlainClimate's dry threshold. The annual average is 51°F. The monthly rows show whether that limited precipitation is spread through the year or concentrated in a shorter interval.
Friday Harbor's cold-season load does not imply a wet climate. Annual precipitation is 18.5 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
These labels group NOAA 1991-2020 normals from Friday Harbor's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Friday Harbor, not an official NOAA class or a year-ahead forecast.
Questions about Friday Harbor's climate
How much rain does Friday Harbor get? ▼
How much energy does heating and cooling require in Friday Harbor? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Friday Harbor's primary station: FRIDAY HARBOR AP (USW00094276). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 5325615). Match rule for Friday Harbor: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Friday Harbor comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.