Photo: Fil.Al from Comox, Canada · CC BY 2.0Winthrop is drier than 92% of U.S. towns: 16 inches of precipitation a year
Deep winter brings January lows near 19°. Winter nights are cold: in January they are colder than in 66% of U.S. towns. The latest 30-year average runs 0.8° warmer than 1901–2000’s, with January up the most. If you like long walks, May, June and September offer highs of 71–77°.
A year in Winthrop at a glance
Each month’s typical high and low, and what it brings.
What stands out about Winthrop’s climate
Compared with towns across the U.S., with Winthrop’s place in Washington beside it.
What a year in Winthrop feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 127 frost-free days a year
In half of years the last 32° night comes by May 15 and the first by September 22. Frost and day counts come from NOAA’s station at Winthrop 1 Wsw, WA, 0.5 miles from the town’s center, at about the same height.
The 2023 USDA map puts Winthrop’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −11°. 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 59 inches of snow a winter
Snow, measured at Winthrop 1 Wsw, WA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 16 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 97 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Winthrop
96% of the work is heating, so the furnace matters far more than the air conditioner. 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 Winthrop 1 Wsw, WA.
Living with Winthrop’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
127 frost-free days in zone 5b. The last frost comes by May 15 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 22.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Winthrop from natural hazards, wildfire is the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Winthrop and similar climates
TownRatings has no climate map of the towns around Winthrop yet.
Climates most like Winthrop’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 |
|---|---|---|---|---|
| Winthrop, WA | 19° | 86° | 16" | 59" |
| Castle Pines, CO | 19° | 86° | 17" | 58" |
| Pocatello, ID | 19° | 87° | 15" | 64" |
| Doney Park, AZ | 17° | 86° | 16" | 52" |
| Livingston, MT | 17° | 85° | 14" | 63" |
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 Winthrop averaged 0.8° warmer than the 1900s. The biggest change is in January (+3.7°).
A smaller shift than in 89% 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 Winthrop compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Winthrop’s place among Washington’s.
Winthrop weather by month
Highs, lows and precipitation from NOAA’s grid at Winthrop’s center; snow, wet days and snow on the ground from Winthrop 1 Wsw, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 19° | 2.3" | 16.6" | 12 | 31 | 18° – 30° |
| February | 39° | 21° | 1.5" | 8.8" | 9 | 28 | 20° – 38° |
| March | 51° | 28° | 1.3" | 3.4" | 8 | 21 | 35° – 46° |
| April | 61° | 35° | 0.9" | 0.1" | 7 | 0 | 43° – 55° |
| May | 71° | 43° | 1.2" | 0.0" | 8 | 0 | 52° – 63° |
| June | 77° | 48° | 1.1" | 0.0" | 7 | 0 | 59° – 70° |
| July | 86° | 54° | 0.6" | 0.0" | 4 | 0 | 63° – 74° |
| August | 86° | 53° | 0.5" | 0.0" | 4 | 0 | 63° – 73° |
| September | 76° | 45° | 0.6" | 0.0" | 4 | 0 | 57° – 66° |
| October | 60° | 35° | 1.5" | 1.1" | 9 | 0 | 42° – 52° |
| November | 42° | 27° | 2.3" | 7.6" | 12 | 10 | 28° – 41° |
| December | 32° | 19° | 2.7" | 21.8" | 13 | 28 | 19° – 32° |
| Year | 59° | 36° | 16.4" | 59.4" | 97 | 119 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 20° to 38°. September is the most reliable, staying within 9°.
Where Winthrop’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 Winthrop’s center.
- Snow: Winthrop 1 Wsw, WA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Winthrop 1 Wsw, WA, 0.5 miles from the town’s center, at about the same height; 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 Winthrop’s climate
What is the weather like in Winthrop?
A typical July afternoon reaches 86°, a January night drops to 19°, and about 59 inches of snow falls in a normal winter. Colder January nights than 66% of U.S. towns; hotter July afternoons than 55% of U.S. towns.
How cold does it get in Winthrop in winter?
January nights average 19°. About 177 nights a year reach 32° or below and 8 reach 0° or below. In the coldest January of the last 30 years the month averaged 18°.
How much snow does Winthrop get?
About 59 inches in a normal winter at Winthrop 1 Wsw, WA, most of it in December, with snow on the ground about 119 days a year.
How hot does it get in Winthrop?
July, with a typical high of 86° and a low of 54°. About 27 days a year reach 90° and 1 reach 100° (Winthrop 1 Wsw, WA).
When is the first and last frost in Winthrop?
In half of years the last spring frost (32°) comes by May 15 and the first fall frost by September 22, about 127 frost-free days, at Winthrop 1 Wsw, WA.
What growing zone is Winthrop in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −11°.
What is the best time of year to visit Winthrop?
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 Winthrop getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 89% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Winthrop.
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.