Cox-Williams House · Photo: Ian Poellet (User:Werewombat) · CC BY-SA 3.0Summers in St. Helens are cooler than in 90% of U.S. towns
January nights here settle around 34°. Winters are mild: January nights here are milder than in 79% of U.S. towns. Compared with 1901–2000, the average now sits 1.3° higher. Keep the boiler serviced for the months from November to March, which average under 50°.
A year in St. Helens at a glance
Each month’s typical high and low, and what it brings.
What stands out about St. Helens’ climate
Compared with towns across the U.S., with St. Helens’ place in Oregon beside it.
What a year in St. Helens feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 201 frost-free days a year
In half of years the last 32° night comes by April 18 and the first by November 7. Frost and day counts come from NOAA’s station at Saint Helens Rfd, OR, 2.7 miles from the town’s center, 200 ft higher.
The 2023 USDA map puts St. Helens’ center in zone 8a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 15°. 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 Battle Ground, WA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 43 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 179 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in St. Helens
94% 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 Saint Helens Rfd, OR.
Living with St. Helens’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
201 frost-free days in zone 8a. The last frost comes by Apr 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 7.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August, September and October. 6.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in St. Helens from natural hazards, earthquakes are the largest share (67%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.
Natural hazards →St. Helens and similar climates
TownRatings has no climate map of the towns around St. Helens yet.
Climates most like St. Helens’, 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 |
|---|---|---|---|---|
| St. Helens, OR | 34° | 81° | 43" | 1.4" |
| Ben Lomond, CA | 40° | 79° | 43" | 0.0" |
| Swannanoa, NC | 27° | 83° | 48" | 2.1" |
| Brigantine, NJ | 28° | 83° | 45" | 10" |
| Marysville, WA | 36° | 75° | 44" | 3.0" |
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 St. Helens averaged 1.3° warmer than the 1900s. The biggest change is in January (+3.1°).
A smaller shift than in 55% 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 St. Helens compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with St. Helens’ place among Oregon’s.
St. Helens weather by month
Highs, lows and precipitation from NOAA’s grid at St. Helens’ center; snow, wet days and snow on the ground from Battle Ground, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 47° | 34° | 6.1" | 0.5" | 21 | 0 | 33° – 45° |
| February | 51° | 34° | 4.5" | 0.3" | 18 | 0 | 38° – 48° |
| March | 56° | 37° | 4.5" | 0.2" | 21 | 0 | 43° – 52° |
| April | 61° | 40° | 3.5" | 0.0" | 18 | 0 | 46° – 55° |
| May | 68° | 46° | 2.5" | 0.0" | 14 | 0 | 52° – 62° |
| June | 73° | 51° | 1.7" | 0.0" | 11 | 0 | 58° – 67° |
| July | 81° | 54° | 0.5" | 0.0" | 4 | 0 | 62° – 71° |
| August | 81° | 54° | 0.6" | 0.0" | 4 | 0 | 64° – 71° |
| September | 76° | 50° | 1.7" | 0.0" | 9 | 0 | 59° – 65° |
| October | 63° | 44° | 3.7" | 0.0" | 16 | 0 | 49° – 58° |
| November | 52° | 38° | 6.4" | 0.0" | 21 | 0 | 39° – 50° |
| December | 45° | 34° | 7.1" | 0.4" | 22 | 0 | 35° – 43° |
| Year | 63° | 43° | 42.7" | 1.4" | 179 | 0 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 33° to 45°. September is the most reliable, staying within 6°.
Where St. Helens’ 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 St. Helens’ center.
- Snow: Battle Ground, WA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Saint Helens Rfd, OR, 2.7 miles from the town’s center, 200 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 St. Helens’ climate
What is the weather like in St. Helens?
A typical July afternoon reaches 81°, a January night drops to 34°, and about 1 inches of snow falls in a normal winter. Milder January nights than 79% of U.S. towns; cooler July afternoons than 90% of U.S. towns.
How cold does it get in St. Helens in winter?
December nights average 34°. About 59 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 35°.
How much snow does St. Helens get?
About 1.4 inches in a normal winter at Battle Ground, WA, most of it in January, with snow on the ground about 0 days a year.
How hot does it get in St. Helens?
July, with a typical high of 81° and a low of 54°. About 20 days a year reach 90° and 2 reach 100° (Saint Helens Rfd, OR).
When is the first and last frost in St. Helens?
In half of years the last spring frost (32°) comes by April 18 and the first fall frost by November 7, about 201 frost-free days, at Saint Helens Rfd, OR.
What growing zone is St. Helens in?
Zone 8a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 15°.
What is the best time of year to visit St. Helens?
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 St. Helens getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 55% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in St. Helens.
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.