Last frost date in St. Helens, Oregon
April 18
Average last frost in spring. In an early year (1 in 10) it's over by March 20; in a late year (1 in 10) it comes after May 26.
November 7
Average first frost in fall. 1 year in 10 it comes by October 21.
Source: NOAA U.S. Climate Normals 1991–2020, station Saint Helens Rfd (USC00357466), 2.7 miles from St. Helens, elevation 269 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Mar 20 | Apr 18 | May 26 |
| First frost in fall | Oct 21 | Nov 7 | Nov 26 |
Frost-free days in an average year: 201
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | May 6 | Oct 24 |
| Frost (32°F) | Every year | Apr 18 | Nov 7 |
| Hard freeze (28°F) | Every year | Mar 24 | Nov 24 |
Nights at 32°F or colder in an average year: 59
What to plant now in St. Helens
- Mustard greensAug 15 – Nov 1Now
- Garden peasSept 1 – Nov 1Now
- ParsleySept 1 – Nov 15Now
- RadishesSept 1 – Nov 15Now
- SpinachSept 15 – Nov 1Now
- Corn saladOct 1 – Dec 1Now
- Onion setsOct 1 – Dec 1Now
- Upland cressOct 1 – Dec 1Now
- Asparagus plantsDec 1 – Jan 1Soon
- Spring planting calendar for an average last frost around April 20 St. Helens: April 18
- Fall planting calendar for an average first frost around November 10 St. Helens: November 7
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in Oregon
- Hillsboro 23 mi · last frost Apr 16
- Portland 23 mi · last frost Feb 25
- Beaverton 26 mi · last frost Apr 1
- Forest Grove 27 mi · last frost Apr 16
- Troutdale 30 mi · last frost Mar 26
Updated