Umatilla, OR climate
Umatilla has mild winters and warm summers, with very little rain. A typical July afternoon reaches 91°, a January night drops to 29°, and about 4 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Umatilla feels like
Winter
Spring
Summer
Fall
Umatilla 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 42° | 29° | 1.2" | 1.2" | 9 | 23° – 42° |
| February | 48° | 30° | 0.8" | 1.4" | 6 | 28° – 44° |
| March | 58° | 34° | 0.8" | 0.2" | 6 | 37° – 50° |
| April | 66° | 40° | 0.7" | 0 | 5 | 49° – 58° |
| May | 75° | 47° | 0.9" | 0 | 5 | 57° – 66° |
| June | 82° | 54° | 0.6" | 0 | 3 | 63° – 75° |
| July | 91° | 59° | 0.2" | 0 | 1 | 68° – 79° |
| August | 90° | 58° | 0.2" | 0 | 2 | 69° – 76° |
| September | 80° | 50° | 0.3" | 0 | 2 | 62° – 69° |
| October | 66° | 40° | 0.8" | 0.1" | 5 | 49° – 58° |
| November | 51° | 33° | 1.0" | 0 | 7 | 35° – 48° |
| December | 41° | 28° | 1.2" | 0.8" | 10 | 28° – 40° |
| Year | 66° | 42° | 8.6" | 3.7" | 62 |
“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 Umatilla
Umatilla gets 9 inches of rain and melted snow a year. December is the wettest month and July the driest. Rain or snow falls on about 62 days a year.
About 221 frost-free days a year
In half of years the last 32° night comes by March 27 and the first one by November 4. That leaves about 221 frost-free days for gardens, longer than 82% of U.S. towns.
Heating and cooling a home in Umatilla
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Umatilla, 85% of that work is heating and 15% 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 Umatilla 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 Umatilla averaged 1.1° warmer than the 1900s. The biggest change is in January (+3.7°). The shift is smaller than in 58% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Umatilla’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. January swings the most: between 1991 and 2020 its average temperature ranged from 23° to 42°. September is the most reliable, staying within 7°.
Common questions about Umatilla’s climate
What is the coldest month in Umatilla?
December, with a typical high of 41° and a low of 28°.
What is the hottest month in Umatilla?
July, with a typical high of 91° and a low of 59°. About 34 days a year reach 90°.
How much snow does Umatilla get?
About 4 inches in a normal winter, most of it in February.
When is the first frost in Umatilla?
In half of years the first 32° night comes by November 4, and the last spring frost by March 27.
What is the rainiest month in Umatilla?
December, with 1.2 inches of rain and melted snow. The year totals 9 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Umatilla itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Boardman, OR (18 mi, snow) and Mcnary Dam, WA (2 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.