Photo: Williamborg · CC BY-SA 3.0Less rain and snow falls on Asotin than on 95% of U.S. towns: 13 inches a year
On a normal January night the air cools to about 30°. Expect the heaviest rain or snow in May and the lightest in August. In July, afternoons here are warmer than in 86% of U.S. towns. Radiators earn their keep from November to March, the months that average under 50°.
A year in Asotin at a glance
Each month’s typical high and low, and what it brings.
What stands out about Asotin’s climate
Compared with towns across the U.S., with Asotin’s place in Washington beside it.
What a year in Asotin feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 200 frost-free days a year
In half of years the last 32° night comes by April 6 and the first by October 26. Frost and day counts come from Lewiston Nez Perce Co Airport, 3 miles away.
The 2023 USDA map puts Asotin’s center in zone 7b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 8°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 13 inches of snow a winter
Snow, measured at Lewiston Nez Perce Co Airport, falls mostly in February and December. Precipitation (rain plus melted snow) adds up to 13 inches a year; May is the wettest month and August the driest. Rain or snow falls on about 106 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Asotin
85% of the work is heating. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Lewiston Nez Perce Co Airport.
Living with Asotin’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
200 frost-free days in zone 7b. The last frost comes by Apr 6 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 26.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.7 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Asotin from natural hazards, river flooding is the largest share (60%); heat waves, cold waves, winter storms and ice storms together are 5%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Asotin and similar climates
TownRatings has no climate map of the towns around Asotin yet.
Climates most like Asotin’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Asotin, WA | 30° | 92° | 13" | 13" |
| Prescott Valley, AZ | 26° | 91° | 14" | 10" |
| Kuna, ID | 24° | 92° | 11" | 18" |
| Portales, NM | 25° | 93° | 16" | 7.6" |
| Spanish Springs, NV | 25° | 91° | 10" | 6.8" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Asotin averaged 1.5° warmer than the 1900s. The biggest change is in January (+3.9°).
A bigger shift than in 58% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Asotin compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Asotin’s place among Washington’s.
Asotin weather by month
Highs, lows and precipitation from NOAA’s grid at Asotin’s center; snow, wet days and snow on the ground from Lewiston Nez Perce Co Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 42° | 30° | 1.1" | 2.7" | 11 | 3 | 27° – 41° |
| February | 48° | 31° | 1.0" | 3.8" | 10 | 3 | 30° – 46° |
| March | 57° | 35° | 1.3" | 0.8" | 12 | 1 | 40° – 51° |
| April | 65° | 40° | 1.4" | 0.0" | 11 | 0 | 47° – 59° |
| May | 74° | 47° | 1.7" | 0.0" | 11 | 0 | 55° – 65° |
| June | 81° | 53° | 1.3" | 0.0" | 9 | 0 | 62° – 74° |
| July | 92° | 58° | 0.5" | 0.0" | 4 | 0 | 65° – 80° |
| August | 92° | 57° | 0.5" | 0.0" | 3 | 0 | 70° – 77° |
| September | 81° | 49° | 0.6" | 0.0" | 5 | 0 | 61° – 70° |
| October | 65° | 40° | 1.1" | 0.0" | 9 | 0 | 47° – 59° |
| November | 50° | 34° | 1.2" | 1.3" | 11 | 1 | 35° – 48° |
| December | 41° | 29° | 1.2" | 4.1" | 11 | 3 | 29° – 39° |
| Year | 65° | 42° | 12.8" | 12.7" | 106 | 11 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 30° to 46°. August is the most reliable, staying within 7°.
Where Asotin’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Asotin’s center.
- Snow: Lewiston Nez Perce Co Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Lewiston Nez Perce Co Airport, 3 miles from the town’s center, 540 ft higher; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Asotin’s climate
What is the weather like in Asotin?
A typical July afternoon reaches 92°, a January night drops to 30°, and about 13 inches of snow falls in a normal winter. Milder January nights than 72% of U.S. towns; hotter July afternoons than 86% of U.S. towns.
How cold does it get in Asotin in winter?
December nights average 29°. About 80 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 29°.
How much snow does Asotin get?
About 13 inches in a normal winter at Lewiston Nez Perce Co Airport, most of it in February and December, with snow on the ground about 11 days a year.
How hot does it get in Asotin?
July, with a typical high of 92° and a low of 58°. About 44 days a year reach 90° and 9 reach 100° (Lewiston Nez Perce Co Airport).
When is the first and last frost in Asotin?
In half of years the last spring frost (32°) comes by April 6 and the first fall frost by October 26, about 200 frost-free days, at Lewiston Nez Perce Co Airport.
What growing zone is Asotin in?
Zone 7b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 8°.
What is the best time of year to visit Asotin?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Asotin getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 58% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Asotin.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.