Three Rivers, OR climate
Three Rivers has chilly, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 83°, a January night drops to 22°, and about 74 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Three Rivers feels like
Winter
Spring
Summer
Fall
Three Rivers 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 | 41° | 22° | 2.9" | 17.9" | 13 | 27 | 24° – 38° |
| February | 43° | 22° | 1.9" | 14.9" | 11 | 22 | 25° – 41° |
| March | 49° | 25° | 2.3" | 8.4" | 12 | 16 | 32° – 44° |
| April | 55° | 28° | 1.5" | 2.0" | 10 | 3 | 36° – 48° |
| May | 64° | 35° | 1.7" | 0.3" | 9 | 0 | 43° – 56° |
| June | 72° | 39° | 0.9" | 0 | 6 | 0 | 51° – 64° |
| July | 83° | 45° | 0.5" | 0 | 3 | 0 | 54° – 68° |
| August | 82° | 44° | 0.5" | 0 | 3 | 0 | 58° – 68° |
| September | 74° | 38° | 0.7" | 0 | 4 | 0 | 52° – 61° |
| October | 60° | 31° | 1.6" | 0.8" | 8 | 1 | 41° – 52° |
| November | 46° | 26° | 2.6" | 8.9" | 12 | 8 | 29° – 41° |
| December | 39° | 21° | 3.6" | 20.7" | 14 | 21 | 24° – 33° |
| Year | 59° | 31° | 20.6" | 73.9" | 102 | 98 |
“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 Three Rivers
Three Rivers gets 21 inches of rain and melted snow a year. December is the wettest month and August the driest. Rain or snow falls on about 102 days a year. Snow covers the ground about 98 days of the year.
A year-round growing season
Heating and cooling a home in Three Rivers
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Three Rivers, 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 Three Rivers 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 Three Rivers averaged 1.0° warmer than the 1900s. The biggest change is in January (+3.5°). The shift is smaller than in 68% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Three Rivers’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 25° to 41°. September is the most reliable, staying within 9°.
Common questions about Three Rivers’s climate
What is the coldest month in Three Rivers?
December, with a typical high of 39° and a low of 21°.
What is the hottest month in Three Rivers?
July, with a typical high of 83° and a low of 45°. About 19 days a year reach 90°.
How much snow does Three Rivers get?
About 74 inches in a normal winter, most of it in December.
When is the first frost in Three Rivers?
Frost is uncommon. Only 100% of years see a night at 32° or below.
What is the rainiest month in Three Rivers?
December, with 3.6 inches of rain and melted snow. The year totals 21 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Three Rivers itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Wickiup Dam, OR (15 mi, snow) and Sunriver, OR (5 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.