Seattle weather in May: Seattle, Washington: normal highs, lows, rain and records for May
Seattle in May has a normal high of 66°F and a normal low of 49°F, a daily mean of 58°F, rising from 63°F on the 1st to 69°F by the 31st. Measurable precipitation falls on 11 days in a normal May, 1.88 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 19°C and low of 9°C, 48 mm of precipitation in May.
- NOAA stationSeattle Tacoma International Airport
- Station IDUSW00024233
- Location47.44°N 122.31°W
- Elevation370 ft (113 m)
- From the center12 miles
- Population780,995
- Jan 48° 38°
- Feb 50° 38°
- Mar 54° 40°
- Apr 59° 43°
- May 66° 49°
- Jun 71° 53°
- Jul 77° 57°
- Aug 78° 57°
- Sep 72° 54°
- Oct 61° 47°
- Nov 52° 41°
- Dec 47° 37°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Seattle in May?
The normal high is 66°F and the normal low 49°F, for a daily mean of 57.5°F. May is 6.2°F warmer than April and 4.5°F cooler than June. May is the 5th warmest month of the year in Seattle and the 8th wettest. Across the month the normal high rises 6°F, from 63°F on May 1 to 69°F on May 31. From one year to the next May's mean temperature typically moves about 2.4°F either way (NOAA's standard deviation), so roughly two Mays in three average between 55°F and 60°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 43%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 63°F | 46°F | 43% | 23% |
| May 8 | 65°F | 47°F | 40% | 21% |
| May 15 | 66°F | 49°F | 38% | 20% |
| May 22 | 68°F | 50°F | 36% | 19% |
| May 31 | 69°F | 51°F | 35% | 18% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 63°F | 46°F | 43% | 23% | 14 h 20 min |
| May 2 | 63°F | 46°F | 43% | 23% | 14 h 30 min |
| May 3 | 64°F | 46°F | 42% | 22% | 14 h 30 min |
| May 4 | 64°F | 46°F | 42% | 22% | 14 h 30 min |
| May 5 | 64°F | 47°F | 41% | 22% | 14 h 40 min |
| May 6 | 64°F | 47°F | 41% | 21% | 14 h 40 min |
| May 7 | 65°F | 47°F | 40% | 21% | 14 h 40 min |
| May 8 | 65°F | 47°F | 40% | 21% | 14 h 50 min |
| May 9 | 65°F | 48°F | 39% | 21% | 14 h 50 min |
| May 10 | 65°F | 48°F | 39% | 20% | 14 h 50 min |
| May 11 | 66°F | 48°F | 38% | 20% | 14 h 50 min |
| May 12 | 66°F | 48°F | 38% | 20% | 15 h |
| May 13 | 66°F | 48°F | 38% | 20% | 15 h |
| May 14 | 66°F | 49°F | 38% | 20% | 15 h |
| May 15 | 66°F | 49°F | 38% | 20% | 15 h |
| May 16 | 67°F | 49°F | 37% | 19% | 15 h 10 min |
| May 17 | 67°F | 49°F | 37% | 19% | 15 h 10 min |
| May 18 | 67°F | 49°F | 37% | 19% | 15 h 10 min |
| May 19 | 67°F | 49°F | 37% | 19% | 15 h 10 min |
| May 20 | 67°F | 50°F | 37% | 19% | 15 h 20 min |
| May 21 | 67°F | 50°F | 36% | 19% | 15 h 20 min |
| May 22 | 68°F | 50°F | 36% | 19% | 15 h 20 min |
| May 23 | 68°F | 50°F | 36% | 19% | 15 h 20 min |
| May 24 | 68°F | 50°F | 36% | 18% | 15 h 30 min |
| May 25 | 68°F | 50°F | 36% | 18% | 15 h 30 min |
| May 26 | 68°F | 51°F | 36% | 18% | 15 h 30 min |
| May 27 | 68°F | 51°F | 35% | 18% | 15 h 30 min |
| May 28 | 68°F | 51°F | 35% | 18% | 15 h 30 min |
| May 29 | 69°F | 51°F | 35% | 18% | 15 h 40 min |
| May 30 | 69°F | 51°F | 35% | 18% | 15 h 40 min |
| May 31 | 69°F | 51°F | 35% | 18% | 15 h 40 min |
- Normal high
- 66°FMay average
- Normal low
- 49°FMay average
- Precipitation
- 1.88 inmonth total
- Days with precipitation
- 110.01 inch or more
- Daylight
- 14 h 20 min to 15 h 40 minMay 1 to May 31
- Days at 70°F or more
- 8
- Days at 80°F or more
- 2
- Sunshine
- 66%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024233; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Seattle in May?
On a given May day the chance of 0.01 inch or more is 38% on average, highest around May 1 (43%). In all, 1.88 in falls on 11 days of a normal May.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024233.
How humid and windy is Seattle in May?
At 3 p.m. the normal temperature is 66°F with 52% relative humidity and a dew point of 48°F; at 6 a.m. it is 53°F with 83% humidity. The wind averages 7.4 mph, most often from the west-southwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 53°F | 48°F | 83% | 6.3 mph | – |
| 9 a.m. | 58°F | 48°F | 71% | 7.2 mph | – |
| noon | 63°F | 49°F | 59% | 8.2 mph | 19% |
| 3 p.m. | 66°F | 48°F | 52% | 9.0 mph | 15% |
| 6 p.m. | 65°F | 48°F | 54% | 8.4 mph | 16% |
| 9 p.m. | 59°F | 48°F | 67% | 7.4 mph | 19% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024233. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for May in Seattle?
The warmest May temperature on this station's record (since 1945) is 93°F, on May 21, 1963; the coldest is 28°F, on May 1, 1954. The wettest May brought 4.76 in (1948).
The May mean against the 1991-2020 normal of 57.5°F: 2021 56.9°F (−0.6), 2022 52.6°F (−4.9), 2023 60.9°F (+3.4), 2024 55.6°F (−1.9), 2025 57.0°F (−0.5), 2026 58.4°F (+0.9). 2 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 56.9°F | −0.6°F | 1.12 in |
| 2022 | 52.6°F | −4.9°F | 3.82 in |
| 2023 | 60.9°F | +3.4°F | 0.93 in |
| 2024 | 55.6°F | −1.9°F | 1.54 in |
| 2025 | 57.0°F | −0.5°F | 0.83 in |
| 2026 | 58.4°F | +0.9°F | 1.14 in |
Source: records: ACIS, station USW00024233; recent months: ACIS, station USW00024233. Records and recent months use complete months only.
How does May in Seattle compare across Washington?
Across the 96 places PlainClimate covers in Washington, May normal highs run from 59°F in Long Beach to 77°F in Pasco; Seattle's is 66°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.