Seattle, 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 Seattle's primary NOAA station, SEATTLE TACOMA INTL AP.
The climate verdict for Seattle
A compact 25.4°F seasonal swing gives Seattle, Washington a steadier-than-extreme annual shape. NOAA reports an annual average of 54°F. Its climate comfort score of 72/100 (good) lands mid-pack nationally, exceeding 66% of station-mapped location scores.
- 54°F
- annual average temperature (NOAA normal)
- 72/100
- comfort score, above 66% of station-mapped location scores
- 39.3"
- annual precipitation · 6" snow
- 266 days
- growing season, frost-free days
Seattle: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00024233 · Seattle, WA 54°F mean · 39.3" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-MID · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 54°F
- RANK-MID #3,842
- PHOTO-FINISH ≈ Tacoma
- PRCP-MID 39.3"
- SWING-NARROW 25°F
- COMF-MID 72/100
- LOAD-HEAT 4,376 HDD
- STN-1 USW00024233
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Tacoma, WA (+ 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.
- Seattle (this station) 54°F
- Cold Renton, WA 54°F
- Hot Seattle Boeing…, WA 54°F
- Near Tacoma, WA 54°F
- Near Kent, WA 54°F
Climate Living Index · Seattle
Seattle: 82/100 · grade B
Seattle publishes all six Living Index dimensions from NOAA annual/seasonal normals · NOAA daily multivariate normals · NOAA hourly normals.
PlainClimate-derived for Seattle, not an official NOAA rating. Rankings still use Comfort Score 72/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Summer moisture balance | 52.3°F mean dew point | 97/100 · A |
| Frost-free season | 266 days/year | 93/100 · A |
| Precipitation balance | 39.3 in · 4.3 from 35 in | 84/100 · B |
| Snowfall burden | 6.3 inches/year | 69/100 · C |
| Annual temperature balance | 53.7°F · 13.8° from 67.5°F | 55/100 · C |
Seattle · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Seattle is a temperate Köppen climate: Csb
Coldest-month mean 42.0°F and warmest-month mean 67.4°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
- 67.4°F
- Coldest month
- 42.0°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 Seattle sits across the climate record
Three NOAA fields for Seattle's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 56th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 56th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 94%
- Warmest-to-coldest month gap for Seattle is compact versus 6,861 complete station-years.
How Seattle compares across U.S. station-mapped locations
Seattle's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
72 Top 34% score exceeds 66% 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%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). This entry sits in this band.
- 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
Seattle's measured station temperature trend
MethodologyAcross 76 complete annual observations from 1950 to 2025, SEATTLE TACOMA INTL AP warmed at a fitted rate of 0.19°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Seattle primary station fitted change +0.19 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 48°F (9°C) | 38°F (3°C) | 43°F (6°C) | 5.8" | 1.8" | 7.0 | 0.0 |
| February | 50°F (10°C) | 38°F (3°C) | 44°F (7°C) | 3.8" | 2.2" | 5.8 | 0.0 |
| March | 54°F (12°C) | 40°F (4°C) | 47°F (8°C) | 4.2" | 0.4" | 1.9 | 0.0 |
| April | 59°F (15°C) | 43°F (6°C) | 51°F (11°C) | 3.2" | 0.0" | 0.1 | 0.0 |
| May | 66°F (19°C) | 49°F (9°C) | 58°F (14°C) | 1.9" | 0.0" | 0.0 | 0.0 |
| June | 71°F (22°C) | 53°F (12°C) | 62°F (17°C) | 1.4" | 0.0" | 0.0 | 0.6 |
| July | 77°F (25°C) | 57°F (14°C) | 67°F (19°C) | 0.6" | 0.0" | 0.0 | 1.8 |
| August | 78°F (25°C) | 57°F (14°C) | 67°F (20°C) | 1.0" | 0.0" | 0.0 | 1.2 |
| September | 72°F (22°C) | 54°F (12°C) | 63°F (17°C) | 1.6" | 0.0" | 0.0 | 0.2 |
| October | 61°F (16°C) | 47°F (8°C) | 54°F (12°C) | 3.9" | 0.0" | 0.2 | 0.0 |
| November | 52°F (11°C) | 41°F (5°C) | 47°F (8°C) | 6.3" | 0.2" | 3.0 | 0.0 |
| December | 47°F (8°C) | 37°F (3°C) | 42°F (6°C) | 5.7" | 1.7" | 7.2 | 0.0 |
The year, day by day
The calendar barely moves in Seattle: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 37°F near December 18 and 79°F near July 28.
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 37°F around December 18.
Where the wet dates fall
The likeliest wet date is January 2, when 61% of years recorded at least a hundredth of an inch. The driest is July 29 at 14%. Summed across the calendar, that is about 157 wet dates a year.
The widest day
July 26 carries the biggest normal gap between afternoon and dawn, 21°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Seattle.
Where Seattle Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 21°F.
Seattle earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 1.8"
18.7 days with precipitation
Snow: 2.2"
15.9 days with precipitation
Snow: 0.4"
17.1 days with precipitation
15.0 days with precipitation
11.3 days with precipitation
9.2 days with precipitation
4.7 days with precipitation
4.9 days with precipitation
8.3 days with precipitation
14.3 days with precipitation
Snow: 0.2"
18.4 days with precipitation
Snow: 1.7"
18.4 days with precipitation
Seattle's wet season runs through the cold months
December, January and February carry 39% of the year's precipitation here, while June through August contribute 8%. 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 25.4°F seasonal spread.
- Wettest month
- November, 6.3"
- Driest month
- July, 0.6"
- Wettest three months
- November, January, December (45% 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.
How Seattle's precipitation splits across the calendar
About 156 days a year record measurable precipitation here, carrying 39.3" between them, or roughly 0.25 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
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.
Snow reaches Seattle, but rarely amounts to much
The normals record 6.3 inches of snow a year here, most likely in February. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation; about 5 days a year record any measurable snow at all.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
November 23
50% probability date
Last Spring Freeze
March 2
50% probability date
Growing Season
266 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,376
Higher = more heating needed
Cooling Degree Days
265
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Humidity & Wind
Monthly averages from hourly observations
| Month | Humidity | Wind (mph) | Clear Sky % | Overcast % |
|---|---|---|---|---|
| January | 78% | 8.3 | 12% | 53% |
| February | 74% | 8.3 | 12% | 46% |
| March | 72% | 8.3 | 9% | 46% |
| April | 68% | 8.0 | 11% | 38% |
| May | 68% | 7.4 | 9% | 34% |
| June | 65% | 7.3 | 16% | 25% |
| July | 64% | 6.8 | 28% | 19% |
| August | 67% | 6.8 | 22% | 20% |
| September | 75% | 6.8 | 27% | 28% |
| October | 79% | 7.6 | 14% | 46% |
| November | 79% | 8.4 | 10% | 52% |
| December | 79% | 8.4 | 10% | 59% |
Nationwide similar cities
Other rankable U.S. places outside WA closest to Seattle 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 (54°F here).
- Beaverton, OR 54°F · 0.0°F off
- Caliente, NV 54°F · 0.0°F off
- Carrollton, MO 54°F · 0.0°F off
- Centralia, KS 54°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (39.3" here), excluding temperature-peer places.
- Webster, NY 39.3" · 0.0" off
- Crystal Lake, IL 39.4" · 0.0" off
- Elizabeth, IL 39.4" · 0.0" off
- Leon, IA 39.3" · 0.0" off
Data-derived climate profile
How Seattle's climate pattern fits together
heating led · moderate · low swing
Heating is the larger measured load in Seattle, at 4,376 degree days versus 265 for cooling. Unlike a strongly continental record, however, its 25.4°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
The frost-free window extends for about 266 days. That is a long calendar measure, but it is not a forecast and does not combine heat, rainfall, soil, or local elevation into a planting recommendation.
Temperature varies within a narrow 25.4°F band across the normal year. August and December mark the typical warm and cold ends of the calendar. The annual average is 54°F. Monthly rows still matter, but they refine a steady profile rather than reveal two climatic extremes.
Seattle's 39.3 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Annual snowfall totals 6.3 inches. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Seattle'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 Seattle, not an official NOAA class or a year-ahead forecast.
Questions about Seattle's climate
How much rain does Seattle get? ▼
How much energy does heating and cooling require in Seattle? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Seattle's primary station: SEATTLE TACOMA INTL AP (USW00024233). 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 5363000). Match rule for Seattle: 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 Seattle 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.