Roche Harbor, WA climate
Roche Harbor has mild winters and cool summers. A typical July afternoon reaches 72°, a January night drops to 38°, and about 6 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Roche Harbor feels like
Winter
Spring
Summer
Fall
Roche Harbor weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 46° | 38° | 3.9" | 1.8" | 15 | 2 | 36° – 46° |
| February | 48° | 37° | 2.4" | 0.4" | 11 | 0 | 36° – 47° |
| March | 52° | 39° | 2.2" | 0.1" | 14 | 0 | 41° – 49° |
| April | 56° | 43° | 1.6" | 0 | 11 | 0 | 45° – 54° |
| May | 63° | 47° | 1.3" | 0 | 9 | 0 | 52° – 58° |
| June | 68° | 51° | 1.0" | 0 | 7 | 0 | 56° – 64° |
| July | 72° | 54° | 0.6" | 0 | 4 | 0 | 60° – 66° |
| August | 72° | 54° | 0.9" | 0 | 5 | 0 | 60° – 65° |
| September | 66° | 51° | 1.4" | 0 | 7 | 0 | 56° – 62° |
| October | 57° | 45° | 3.0" | 0.1" | 12 | 0 | 49° – 55° |
| November | 50° | 41° | 4.3" | 0.6" | 15 | 1 | 42° – 49° |
| December | 46° | 37° | 3.7" | 2.8" | 15 | 2 | 37° – 44° |
| Year | 58° | 45° | 26.4" | 5.8" | 125 | 5 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Roche Harbor
Roche Harbor gets 26 inches of rain and melted snow a year. November is the wettest month and July the driest. Rain or snow falls on about 125 days a year.
About 230 frost-free days a year
In half of years the last 32° night comes by March 26 and the first one by November 10. That leaves about 230 frost-free days for gardens, longer than 86% of U.S. towns.
Heating and cooling a home in Roche Harbor
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Roche Harbor, 99% of that work is heating and 1% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Roche Harbor compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Roche Harbor averaged 1.0° warmer than the 1900s. The biggest change is in January (+2.4°). The shift is smaller than in 67% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Roche Harbor’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 36° to 47°. August is the most reliable, staying within 5°.
Common questions about Roche Harbor’s climate
What is the coldest month in Roche Harbor?
February, with a typical high of 48° and a low of 37°.
What is the hottest month in Roche Harbor?
July, with a typical high of 72° and a low of 54°.
How much snow does Roche Harbor get?
About 6 inches in a normal winter, most of it in December.
When is the first frost in Roche Harbor?
In half of years the first 32° night comes by November 10, and the last spring frost by March 26.
What is the rainiest month in Roche Harbor?
November, with 4.3 inches of rain and melted snow. The year totals 26 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Roche Harbor itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Olga 2 Se, WA (15 mi, snow) and Friday Harbor Airport, WA (8 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.