Snohomish County climate

Snohomish County Weather in May

NOAA 1991-2020 normals for Startup 1 E, 20 km from Snohomish County

Average highs run from 64°F on May 1 to 69°F on May 31, and lows from 41°F to 47°F. Normal precipitation for the month is 4.95 in over about 15 wet days.

May day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Snohomish County, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

May at a glance

Average high
67°F
Average low
44°F
Precipitation
4.95 in
Record high
91°FMay 2, 2016
Record low
30°FMay 1, 2017
Chance of a freeze
22%
Daylight
14 h 33 min to 15 h 46 min
Cloud cover
71%
Humidity
81%
Dew point
39°F
Wind
3.6 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
May 164°F41°F89°F 201430°F 201754%0%
May 264°F42°F91°F 201631°F 201554%0%
May 364°F42°F78°F 201833°F 201153%0%
May 465°F42°F78°F 201335°F 201153%0%
May 565°F42°F82°F 201331°F 197853%0%
May 665°F42°F86°F 201332°F 197852%0%
May 765°F43°F81°F 201632°F 201752%0%
May 865°F43°F83°F 202035°F 201751%0%
May 966°F43°F85°F 202037°F 201651%0%
May 1066°F43°F87°F 201933°F 201251%0%
May 1166°F43°F86°F 201936°F 201251%0%
May 1266°F44°F79°F 201233°F 197750%0%
May 1366°F44°F85°F 201637°F 197750%0%
May 1467°F44°F87°F 201839°F 201750%0%
May 1567°F44°F82°F 201435°F 201750%0%
May 1667°F45°F72°F 201335°F 201750%0%
May 1767°F45°F72°F 201636°F 201150%0%
May 1867°F45°F78°F 201536°F 201150%0%
May 1967°F45°F75°F 201838°F 201150%0%
May 2067°F45°F81°F 197840°F 201850%0%
May 2168°F46°F83°F 197843°F 201351%0%
May 2268°F46°F84°F 201739°F 197751%0%
May 2368°F46°F80°F 201938°F 201351%0%
May 2468°F46°F72°F 201836°F 197851%0%
May 2568°F46°F73°F 201237°F 197751%0%
May 2668°F46°F80°F 201740°F 201651%0%
May 2768°F47°F87°F 201741°F 197751%0%
May 2868°F47°F87°F 201742°F 201851%0%
May 2968°F47°F80°F 201535°F 201651%0%
May 3068°F47°F78°F 201937°F 197851%0%
May 3169°F47°F80°F 201641°F 197851%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Snohomish County, in percent, and of at least 0.1 inch of snowfall.02040601102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

May 1
sunrise 5:48 AM, sunset 8:21 PM
May 31
sunrise 5:12 AM, sunset 8:58 PM

Every day of May: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00458034 (Startup 1 E), public domain. Records: NOAA GHCN-Daily, station USC00450257, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.