Photo: M.O. Stevens · CC BY 3.0Afternoon heat in Wilsonville trails that of 84% of U.S. towns
The depth of winter brings overnight lows near 36°. Winters are mild: January nights here are milder than in 83% of U.S. towns. The latest 30-year average runs 1.2° warmer than 1901–2000’s, with January up the most. Central heating does most of its work from November to March, in months below 50° on average.
A year in Wilsonville at a glance
Each month’s typical high and low, and what it brings.
What stands out about Wilsonville’s climate
Compared with towns across the U.S., with Wilsonville’s place in Oregon beside it.
What a year in Wilsonville feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 243 frost-free days a year
In half of years the last 32° night comes by March 18 and the first by November 13. Frost and day counts come from NOAA’s station at N Willamette Exp Stn, OR, 2.2 miles from the town’s center, at about the same height.
The 2023 USDA map puts Wilsonville’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 20°. 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 1 inches of snow a winter
Snow, measured at Rex 1 S, OR, falls mostly in January. Precipitation (rain plus melted snow) adds up to 40 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 153 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Wilsonville
92% 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 N Willamette Exp Stn, OR.
Living with Wilsonville’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
243 frost-free days in zone 9a. The last frost comes by Mar 18 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 13.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 18 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Wilsonville from natural hazards, earthquakes are the largest share (58%); heat waves, cold waves, winter storms and ice storms together are 15%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Wilsonville and similar climates
TownRatings has no climate map of the towns around Wilsonville yet.
Climates most like Wilsonville’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 |
|---|---|---|---|---|
| Wilsonville, OR | 36° | 82° | 40" | 1.0" |
| Scotts Valley, CA | 39° | 79° | 37" | 0.0" |
| Mercer Island, WA | 37° | 77° | 37" | 3.8" |
| Swannanoa, NC | 27° | 83° | 48" | 2.1" |
| Brigantine, NJ | 28° | 83° | 45" | 10" |
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 Wilsonville averaged 1.2° warmer than the 1900s. The biggest change is in January (+2.8°).
A smaller 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 Wilsonville compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Wilsonville’s place among Oregon’s.
Wilsonville weather by month
Highs, lows and precipitation from NOAA’s grid at Wilsonville’s center; snow, wet days and snow on the ground from Rex 1 S, OR. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 48° | 36° | 5.8" | 0.6" | 20 | 0 | 35° – 46° |
| February | 51° | 36° | 4.2" | 0.1" | 16 | 0 | 37° – 49° |
| March | 56° | 39° | 4.4" | 0.2" | 18 | 0 | 44° – 52° |
| April | 61° | 42° | 3.3" | 0.0" | 15 | 0 | 47° – 56° |
| May | 69° | 47° | 2.4" | 0.0" | 11 | 0 | 52° – 62° |
| June | 74° | 51° | 1.5" | 0.0" | 8 | 0 | 59° – 68° |
| July | 82° | 55° | 0.4" | 0.0" | 3 | 0 | 63° – 72° |
| August | 82° | 55° | 0.5" | 0.0" | 3 | 0 | 65° – 72° |
| September | 76° | 51° | 1.5" | 0.0" | 7 | 0 | 60° – 66° |
| October | 64° | 45° | 3.8" | 0.0" | 13 | 0 | 51° – 58° |
| November | 53° | 39° | 6.0" | 0.0" | 19 | 0 | 40° – 51° |
| December | 46° | 35° | 6.8" | 0.1" | 20 | 0 | 36° – 44° |
| Year | 63° | 44° | 40.4" | 1.0" | 153 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 37° to 49°. September is the most reliable, staying within 6°.
Where Wilsonville’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 Wilsonville’s center.
- Snow: Rex 1 S, OR.
- Frost, freezing nights, 90° and 100° days, heating and cooling: N Willamette Exp Stn, OR, 2.2 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 Wilsonville’s climate
What is the weather like in Wilsonville?
A typical July afternoon reaches 82°, a January night drops to 36°, and about 1 inches of snow falls in a normal winter. Milder January nights than 83% of U.S. towns; cooler July afternoons than 84% of U.S. towns.
How cold does it get in Wilsonville in winter?
December nights average 35°. About 45 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 36°.
How much snow does Wilsonville get?
About 1.0 inches in a normal winter at Rex 1 S, OR, most of it in January, with snow on the ground about 0 days a year.
How hot does it get in Wilsonville?
July, with a typical high of 82° and a low of 55°. About 16 days a year reach 90° and 2 reach 100° (N Willamette Exp Stn, OR).
When is the first and last frost in Wilsonville?
In half of years the last spring frost (32°) comes by March 18 and the first fall frost by November 13, about 243 frost-free days, at N Willamette Exp Stn, OR.
What growing zone is Wilsonville in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 20°.
What is the best time of year to visit Wilsonville?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Wilsonville getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Wilsonville.
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.