Dayton, WA climate
Dayton has chilly winters and warm summers, with very little rain. A typical July afternoon reaches 88°, a January night drops to 28°, and about 16 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Dayton feels like
Winter
Spring
Summer
Fall
Dayton 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 | 41° | 28° | 2.3" | 6.3" | 14 | 24° – 41° |
| February | 46° | 29° | 1.9" | 1.9" | 12 | 27° – 43° |
| March | 54° | 33° | 2.4" | 1.0" | 13 | 37° – 48° |
| April | 62° | 37° | 2.0" | 0.1" | 12 | 44° – 56° |
| May | 70° | 44° | 2.0" | 0 | 10 | 52° – 62° |
| June | 78° | 50° | 1.4" | 0 | 7 | 59° – 72° |
| July | 88° | 55° | 0.5" | 0 | 3 | 63° – 76° |
| August | 88° | 54° | 0.5" | 0 | 3 | 66° – 75° |
| September | 77° | 47° | 0.8" | 0 | 5 | 59° – 67° |
| October | 63° | 38° | 1.8" | 0.1" | 10 | 44° – 56° |
| November | 48° | 32° | 2.7" | 1.2" | 14 | 33° – 46° |
| December | 40° | 27° | 2.5" | 5.2" | 14 | 27° – 37° |
| Year | 63° | 39° | 20.8" | 15.8" | 117 |
“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 Dayton
Dayton gets 21 inches of rain and melted snow a year. November is the wettest month and July the driest. Rain or snow falls on about 117 days a year.
About 168 frost-free days a year
In half of years the last 32° night comes by April 28 and the first one by October 13. That leaves about 168 frost-free days for gardens, shorter than 63% of U.S. towns.
Heating and cooling a home in Dayton
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Dayton, 91% of that work is heating and 9% 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 Dayton 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 Dayton averaged 1.5° warmer than the 1900s. The biggest change is in January (+4.1°). The shift is larger than in 68% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Dayton’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 24° to 41°. September is the most reliable, staying within 8°.
Common questions about Dayton’s climate
What is the coldest month in Dayton?
December, with a typical high of 40° and a low of 27°.
What is the hottest month in Dayton?
July, with a typical high of 88° and a low of 55°. About 31 days a year reach 90°.
How much snow does Dayton get?
About 16 inches in a normal winter, most of it in January.
When is the first frost in Dayton?
In half of years the first 32° night comes by October 13, and the last spring frost by April 28.
What is the rainiest month in Dayton?
November, with 2.7 inches of rain and melted snow. The year totals 21 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Dayton itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Dayton 1 Wsw, WA (1 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.