Frost dates for Mazama, WA
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
May 9
typical year
Safe to plant
May 24
frost is over in 9 of 10 years
First fall frost
September 29
typical year
Growing season
142 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 | – | Apr 11 – 25 | – |
| Spinach | – | Mar 28 – Apr 18 | Aug 4 – 18 |
| Lettuce | – | Apr 11 – May 2 | Aug 4 – 18 |
| Radishes | – | Apr 11 – May 23 | Aug 18 – Sep 1 |
| Onions | – | Apr 11 – 25 | – |
| Potatoes | – | Apr 18 – May 2 | – |
| Carrots | – | Apr 18 – May 9 | Jul 7 – 21 |
| Beets | – | Apr 11 – 25 | Jul 21 – Aug 4 |
| Kale | Feb 28 – Mar 14 | Apr 11 – 25 | Jul 21 – Aug 4 |
| Broccoli | Feb 28 – Mar 14 | Apr 25 – May 9 | Jul 21 – Aug 4 |
| Cabbage | Feb 14 – 28 | Apr 11 – 25 | Jul 21 – Aug 4 |
| Garlic | – | – | Aug 18 – Sep 8 |
| Warm-season crops | |||
| Tomatoes | Mar 29 – Apr 12 | May 24 – Jun 7 | – |
| Peppers | Mar 22 – Apr 5 | May 31 – Jun 14 | – |
| Cucumbers | – | May 24 – Jun 14 | – |
| Zucchini | – | May 24 – Jun 21 | – |
| Pumpkins | – | May 24 – Jun 14 | – |
| Green beans | – | May 24 – Jul 21 | – |
| Sweet corn | – | May 24 – Jun 21 | – |
| Basil | Apr 19 – May 3 | May 31 – Jun 7 | – |
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 24 | May 9 | April 28 |
| Fall frost before | September 15 | September 29 | October 10 |
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 April 25 (May 9 in a late year), and the first one in fall around October 10.
Where these dates come from
NOAA weather station MAZAMA, WA US (USC00455133), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 12 miles:
98833
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.