Frost dates for Kennewick, 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
March 28
typical year
Safe to plant
April 10
frost is over in 9 of 10 years
First fall frost
October 30
typical year
Growing season
216 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 | – | Feb 28 – Mar 14 | – |
| Spinach | – | Feb 14 – Mar 7 | Sep 4 – 18 |
| Lettuce | – | Feb 28 – Mar 21 | Sep 4 – 18 |
| Radishes | – | Feb 28 – Apr 11 | Sep 18 – Oct 2 |
| Onions | – | Feb 28 – Mar 14 | – |
| Potatoes | – | Mar 7 – 21 | – |
| Carrots | – | Mar 7 – 28 | Aug 7 – 21 |
| Beets | – | Feb 28 – Mar 14 | Aug 21 – Sep 4 |
| Kale | Jan 17 – 31 | Feb 28 – Mar 14 | Aug 21 – Sep 4 |
| Broccoli | Jan 17 – 31 | Mar 14 – 28 | Aug 21 – Sep 4 |
| Cabbage | Jan 3 – 17 | Feb 28 – Mar 14 | Aug 21 – Sep 4 |
| Garlic | – | – | Sep 18 – Oct 9 |
| Warm-season crops | |||
| Tomatoes | Feb 13 – 27 | Apr 10 – 24 | – |
| Peppers | Feb 6 – 20 | Apr 17 – May 1 | – |
| Cucumbers | – | Apr 10 – May 1 | – |
| Zucchini | – | Apr 10 – May 8 | – |
| Pumpkins | – | Apr 10 – May 1 | – |
| Green beans | – | Apr 10 – Aug 21 | – |
| Sweet corn | – | Apr 10 – May 8 | – |
| Basil | Mar 6 – 20 | Apr 17 – 24 | – |
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 | April 10 | March 28 | March 9 |
| Fall frost before | October 18 | October 30 | November 15 |
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 8 (March 29 in a late year), and the first one in fall around November 11.
Towns that use these dates
This is the nearest NOAA station with frost records for 2 towns.
Kennewick, Pasco
Where these dates come from
NOAA weather station KENNEWICK, WA US (USC00454154), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 11 miles:
99336, 99337, 99338
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.