Photo: Andrew Filer (In memoriam afiler) · CC BY-SA 2.0Dry weather: only 18 inches of rain and melted snow a year in Rosalia, less than in 90% of U.S. towns
Midwinter brings lows of about 25°. December is the wettest month here, with about 5.7 times the rain of August. By January nights alone, it runs milder than 63% of U.S. towns. Seedlings are safe outdoors from about May 7, with the first autumn frost due around September 28.
A year in Rosalia at a glance
Each month’s typical high and low, and what it brings.
What stands out about Rosalia’s climate
Compared with towns across the U.S., with Rosalia’s place in Washington beside it.
What a year in Rosalia feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 144 frost-free days a year
In half of years the last 32° night comes by May 7 and the first by September 28. Frost and day counts come from NOAA’s station at Rosalia, WA, 0.6 miles from the town’s center, 140 ft higher.
The 2023 USDA map puts Rosalia’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −2°. 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 26 inches of snow a winter
Snow, measured at Rosalia, WA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 18 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 104 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Rosalia
95% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Rosalia, WA.
Living with Rosalia’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
144 frost-free days in zone 6b. The last frost comes by May 7 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 28.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 0.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Rosalia from natural hazards, river flooding is the largest share (72%); heat waves, cold waves, winter storms and ice storms together are 16%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Rosalia and similar climates
TownRatings has no climate map of the towns around Rosalia yet.
Climates most like Rosalia’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 |
|---|---|---|---|---|
| Rosalia, WA | 25° | 84° | 18" | 26" |
| Deschutes River Woods, OR | 24° | 84° | 13" | 22" |
| Polson, MT | 20° | 83° | 19" | 34" |
| Ruidoso, NM | 22° | 82° | 20" | 26" |
| Cimarron Hills, CO | 18° | 85° | 17" | 33" |
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 Rosalia averaged 1.5° warmer than the 1900s. The biggest change is in January (+4.3°).
A bigger shift than in 60% 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 Rosalia compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Rosalia’s place among Washington’s.
Rosalia weather by month
Highs, lows and precipitation from NOAA’s grid at Rosalia’s center; snow, wet days and snow on the ground from Rosalia, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 37° | 25° | 2.2" | 6.4" | 12 | 20° – 38° |
| February | 42° | 27° | 1.6" | 3.2" | 9 | 22° – 41° |
| March | 49° | 31° | 1.9" | 1.6" | 11 | 33° – 45° |
| April | 57° | 35° | 1.6" | 0.2" | 10 | 41° – 54° |
| May | 66° | 42° | 1.7" | 0.0" | 9 | 49° – 59° |
| June | 73° | 47° | 1.4" | 0.0" | 8 | 56° – 68° |
| July | 84° | 51° | 0.5" | 0.0" | 4 | 60° – 73° |
| August | 84° | 51° | 0.4" | 0.0" | 3 | 62° – 71° |
| September | 74° | 44° | 0.6" | 0.0" | 4 | 55° – 64° |
| October | 59° | 35° | 1.6" | 0.1" | 8 | 42° – 54° |
| November | 44° | 30° | 2.3" | 3.9" | 13 | 29° – 44° |
| December | 36° | 25° | 2.4" | 10.8" | 12 | 24° – 35° |
| Year | 59° | 37° | 18.3" | 26.2" | 104 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 22° to 41°. September is the most reliable, staying within 8°.
Where Rosalia’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 Rosalia’s center.
- Snow: Rosalia, WA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rosalia, WA, 0.6 miles from the town’s center, 140 ft higher; the nearest station that passes our checks for distance, height and agreement with the grid.
- 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 Rosalia’s climate
What is the weather like in Rosalia?
A typical July afternoon reaches 84°, a January night drops to 25°, and about 26 inches of snow falls in a normal winter. Milder January nights than 63% of U.S. towns; cooler July afternoons than 59% of U.S. towns.
How cold does it get in Rosalia in winter?
December nights average 25°. About 146 nights a year reach 32° or below and 3 reach 0° or below. In the coldest December of the last 30 years the month averaged 24°.
How much snow does Rosalia get?
About 26 inches in a normal winter at Rosalia, WA, most of it in December.
How hot does it get in Rosalia?
July, with a typical high of 84° and a low of 51°. About 25 days a year reach 90° and 2 reach 100° (Rosalia, WA).
When is the first and last frost in Rosalia?
In half of years the last spring frost (32°) comes by May 7 and the first fall frost by September 28, about 144 frost-free days, at Rosalia, WA.
What growing zone is Rosalia in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −2°.
What is the best time of year to visit Rosalia?
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 Rosalia getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Rosalia.
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.