Frost dates for Riverside, 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
June 7
typical year
Safe to plant
June 28
frost is over in 9 of 10 years
First fall frost
September 6
typical year
Growing season
89 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 | – | May 10 – 24 | – |
| Spinach | – | Apr 26 – May 17 | Jul 12 – 26 |
| Lettuce | – | May 10 – 31 | Jul 12 – 26 |
| Radishes | – | May 10 – Jun 21 | Jul 26 – Aug 9 |
| Onions | – | May 10 – 24 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 17 – Jun 7 | Jun 14 – 28 |
| Beets | – | May 10 – 24 | Jun 28 – Jul 12 |
| Kale | Mar 29 – Apr 12 | May 10 – 24 | Jun 28 – Jul 12 |
| Broccoli | Mar 29 – Apr 12 | May 24 – Jun 7 | Jun 28 – Jul 12 |
| Cabbage | Mar 15 – 29 | May 10 – 24 | Jun 28 – Jul 12 |
| Garlic | – | – | Jul 26 – Aug 16 |
| Warm-season crops | |||
| Tomatoes | Season usually too short. Try a quick variety or row covers. | ||
| Peppers | Season usually too short. Try a quick variety or row covers. | ||
| Cucumbers | – | Jun 28 – Jul 19 | – |
| Zucchini | – | Jun 28 – Jul 26 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 28 | – |
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | May 24 – Jun 7 | Jul 5 – 12 | – |
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 | June 28 | June 7 | May 21 |
| Fall frost before | August 22 | September 6 | September 22 |
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 May 20 (June 10 in a late year), and the first one in fall around September 19.
Where these dates come from
NOAA weather station RIVERSIDE 7 SSW, OR US (USC00357208), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 21 miles:
97732, 97906, 97917
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.