San Juan County climate

San Juan County Weather in April

NOAA 1991-2020 normals for Friday Harbor AP, 1 km from San Juan County

Average highs run from 55°F on April 1 to 60°F on April 30, and lows from 40°F to 42°F. Normal precipitation for the month is 1.01 in over about 10 wet days.

April day by day

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

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

April at a glance

Average high
57°F
Average low
41°F
Precipitation
1.01 in
Record high
81°FApr 25, 2025
Record low
27°FApr 1, 2008
Chance of a freeze
35%
Daylight
12 h 53 min to 14 h 32 min
Cloud cover
73%
Humidity
80%
Dew point
42°F
Wind
6.7 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
Apr 155°F40°F63°F 201927°F 200841%0%
Apr 255°F40°F66°F 201930°F 200241%0%
Apr 355°F40°F65°F 200429°F 200841%0%
Apr 456°F40°F62°F 201929°F 200940%0%
Apr 556°F40°F69°F 202531°F 201240%0%
Apr 656°F40°F69°F 200730°F 201239%0%
Apr 756°F40°F65°F 201630°F 201239%0%
Apr 856°F40°F65°F 201630°F 199838%0%
Apr 956°F40°F64°F 202030°F 200838%0%
Apr 1056°F40°F67°F 200433°F 201038%0%
Apr 1157°F40°F73°F 200431°F 202137%0%
Apr 1257°F40°F64°F 200832°F 202137%0%
Apr 1357°F41°F63°F 201431°F 200136%0%
Apr 1457°F41°F68°F 201930°F 199936%0%
Apr 1557°F41°F69°F 202131°F 200935%0%
Apr 1657°F41°F71°F 202133°F 202635%0%
Apr 1758°F41°F73°F 202134°F 199835%0%
Apr 1858°F41°F79°F 201632°F 201134%0%
Apr 1958°F41°F75°F 201633°F 200734%0%
Apr 2058°F41°F76°F 201632°F 200734%0%
Apr 2158°F41°F66°F 202132°F 200834%0%
Apr 2259°F41°F71°F 200533°F 200833%0%
Apr 2359°F41°F67°F 200534°F 200233%0%
Apr 2459°F41°F71°F 200630°F 200033%0%
Apr 2559°F41°F81°F 202532°F 200833%0%
Apr 2659°F41°F73°F 201831°F 200832%0%
Apr 2760°F42°F71°F 200536°F 201932%0%
Apr 2860°F42°F68°F 202333°F 199932%0%
Apr 2960°F42°F70°F 199835°F 200232%0%
Apr 3060°F42°F76°F 200435°F 201332%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at San Juan County, in percent, and of at least 0.1 inch of snowfall.010203040501102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (PDT).

April 1
sunrise 6:50 AM, sunset 7:43 PM
April 30
sunrise 5:54 AM, sunset 8:26 PM

Every day of April: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00094276 (Friday Harbor AP), public domain. Records: NOAA GHCN-Daily, station USW00094276, 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.