Frost dates for St. Helens, OR
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
April 18
typical year
Safe to plant
May 26
frost is over in 9 of 10 years
First fall frost
November 7
typical year
Growing season
201 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Mar 21 – Apr 4 | – |
| Spinach | – | Mar 7 – 28 | Sep 12 – 26 |
| Lettuce | – | Mar 21 – Apr 11 | Sep 12 – 26 |
| Radishes | – | Mar 21 – May 2 | Sep 26 – Oct 10 |
| Onions | – | Mar 21 – Apr 4 | – |
| Potatoes | – | Mar 28 – Apr 11 | – |
| Carrots | – | Mar 28 – Apr 18 | Aug 15 – 29 |
| Beets | – | Mar 21 – Apr 4 | Aug 29 – Sep 12 |
| Kale | Feb 7 – 21 | Mar 21 – Apr 4 | Aug 29 – Sep 12 |
| Broccoli | Feb 7 – 21 | Apr 4 – 18 | Aug 29 – Sep 12 |
| Cabbage | Jan 24 – Feb 7 | Mar 21 – Apr 4 | Aug 29 – Sep 12 |
| Garlic | – | – | Sep 26 – Oct 17 |
| Warm-season crops | |||
| Tomatoes | Mar 31 – Apr 14 | May 26 – Jun 9 | – |
| Peppers | Mar 24 – Apr 7 | Jun 2 – 16 | – |
| Cucumbers | – | May 26 – Jun 16 | – |
| Zucchini | – | May 26 – Jun 23 | – |
| Pumpkins | – | May 26 – Jun 16 | – |
| Green beans | – | May 26 – Aug 29 | – |
| Sweet corn | – | May 26 – Jun 23 | – |
| Basil | Apr 21 – May 5 | Jun 2 – 9 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | May 26 | April 18 | March 20 |
| Fall frost before | October 21 | November 7 | November 26 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around March 24 (May 6 in a late year), and the first one in fall around November 24.
Towns that use these dates
This is the nearest NOAA station with frost records for 3 towns.
St. Helens, Woodland, WA, Columbia City
Where these dates come from
NOAA weather station SAINT HELENS RFD, OR US (USC00357466), 1991–2020 climate normals. It's the nearest station for 5 zip codes, all within 12 miles:
97018, 97051, 97053, 97054, 98674
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.