Snohomish County climate

Snohomish County Weather in December

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

Average highs run from 48°F on December 1 to 46°F on December 31, and lows from 35°F to 33°F. Normal precipitation for the month is 8.41 in over about 20 wet days.

December 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.020406080151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

December at a glance

Average high
47°F
Average low
34°F
Precipitation
8.41 in
Snowfall
0.2 in
Record high
66°FDec 10, 2014
Record low
9°FDec 31, 1978
Chance of a freeze
100%
Daylight
8 h 40 min to 8 h 26 min
Cloud cover
72%
Humidity
96%
Dew point
24°F
Wind
4.7 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
Dec 148°F35°F54°F 201510°F 201466%1%
Dec 248°F35°F54°F 201511°F 201466%1%
Dec 348°F35°F58°F 201517°F 201465%1%
Dec 448°F35°F54°F 201217°F 201365%1%
Dec 548°F34°F51°F 201413°F 201365%1%
Dec 647°F34°F55°F 201512°F 201365%1%
Dec 747°F34°F56°F 201510°F 201365%1%
Dec 847°F34°F61°F 201414°F 201365%1%
Dec 947°F34°F62°F 201419°F 201365%1%
Dec 1047°F34°F66°F 201422°F 201165%1%
Dec 1147°F34°F58°F 201422°F 201165%1%
Dec 1247°F34°F50°F 197721°F 201165%1%
Dec 1346°F34°F54°F 201817°F 201665%2%
Dec 1446°F33°F61°F 201817°F 201665%2%
Dec 1546°F33°F54°F 197613°F 201664%2%
Dec 1646°F33°F59°F 197613°F 201664%2%
Dec 1746°F33°F60°F 197613°F 201664%2%
Dec 1846°F33°F53°F 201820°F 201364%2%
Dec 1946°F33°F55°F 201820°F 201364%2%
Dec 2046°F33°F56°F 201824°F 201664%2%
Dec 2146°F33°F52°F 201423°F 201164%2%
Dec 2246°F33°F49°F 201223°F 201164%2%
Dec 2346°F33°F52°F 201422°F 201764%2%
Dec 2446°F33°F50°F 201822°F 201664%2%
Dec 2546°F33°F50°F 201120°F 201664%2%
Dec 2646°F33°F53°F 197625°F 197764%2%
Dec 2746°F33°F54°F 197621°F 197764%2%
Dec 2846°F33°F55°F 201120°F 197864%2%
Dec 2946°F33°F56°F 201715°F 197864%2%
Dec 3046°F33°F55°F 197610°F 197864%2%
Dec 3146°F33°F52°F 20199°F 197864%2%

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.0204060801102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PST).

December 1
sunrise 7:36 AM, sunset 4:16 PM
December 31
sunrise 7:57 AM, sunset 4:23 PM

Every day of December: 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.