Monroe, WA frost dates
Last spring frostApr 17median date
First fall frostOct 23median date
Growing season189 daysfrost-free
Hardiness zone8bZone 8b
How Monroe compares
- In 8 years out of 10, the last spring frost in Monroe falls between March 29 and May 7, a 39-day window. The first fall frost falls between October 7 and November 9.
- The median last frost is 4 days earlier than the Washington median of Apr 21.
- Its 189-day growing season is longer than 55% of the 491 Washington places with a regular frost season (state median 182 days).
- The last frost is 32 days later than the zone 8b median of Mar 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 8b chart.
- The weather station records an average of 60 nights a year at or below 32°F.
- Compared with Everett, WA, 22 km away, the last frost here is 39 days later than there and the growing season is 64 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 29 |
| 50% (median) | April 17 |
| 10% (safe for tender plants) | May 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 7 |
| 50% (median) | October 23 |
| 90% (late) | November 9 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Monroe, WA
Monroe, WA frost dates — last frost Apr 17, first frost Oct 23, zone 8b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Jan 23 to Feb 6Transplant outside: Mar 20 to Apr 3
Start indoors: Feb 6 to Feb 20Transplant outside: May 1 to May 15
Start indoors: Feb 6 to Feb 20Transplant outside: May 1 to May 15
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 24 to May 8
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 20 to Apr 24Plant for fall: Aug 28 to Sep 25
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 20 to Apr 3Sow outdoors: Mar 20 to Apr 3Plant for fall: Aug 14 to Sep 4
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 17 to Aug 7
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 17 to Aug 7
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 17 to Aug 7
Start indoors: Mar 6 to Mar 20Transplant outside: May 8 to May 22Sow outdoors: May 8 to May 22
Start indoors: Mar 6 to Mar 20Transplant outside: Apr 24 to May 8
Sow outdoors: Mar 6 to Mar 27Plant for fall: Jul 31 to Aug 21
Sow outdoors: Mar 6 to Mar 27Plant for fall: Aug 28 to Sep 18
Sow outdoors: Mar 13 to Apr 24Plant for fall: Sep 11 to Oct 2
Start indoors: Mar 20 to Mar 27Transplant outside: May 1 to May 8Sow outdoors: Apr 24 to May 8Plant for fall: Aug 7 to Aug 21
Start indoors: Mar 20 to Mar 27Sow outdoors: Apr 24 to May 8Plant for fall: Aug 14 to Aug 28
Start indoors: Mar 20 to Mar 27Sow outdoors: Apr 24 to May 8
Start indoors: Mar 20 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 27 to Apr 24Plant for fall: Jul 31 to Aug 14
Sow outdoors: Mar 27 to Apr 24Plant for fall: Aug 14 to Aug 28
Sow outdoors: Mar 27 to Apr 17
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 14 to Aug 28
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 28 to Sep 18
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 7 to Aug 21
Sow outdoors: Apr 24 to May 8
Transplant outside: May 1 to May 22
Plant for fall: Oct 9 to Nov 13
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Monroe, WA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 23 – Feb 6 | Mar 20 – Apr 3 | — | — |
| Peppers | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Eggplant | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Tomatoes | Feb 20 – Mar 6 | Apr 24 – May 8 | — | — |
| Lettuce | Feb 20 – Mar 6 | Mar 27 – Apr 10 | Mar 20 – Apr 24 | Aug 28 – Sep 25 |
| Kale | Feb 20 – Mar 6 | Mar 20 – Apr 3 | Mar 20 – Apr 3 | Aug 14 – Sep 4 |
| Broccoli | Feb 20 – Mar 6 | Apr 3 – Apr 17 | — | Jul 17 – Aug 7 |
| Cabbage | Feb 20 – Mar 6 | Mar 27 – Apr 10 | — | Jul 17 – Aug 7 |
| Cauliflower | Feb 20 – Mar 6 | Apr 3 – Apr 17 | — | Jul 17 – Aug 7 |
| Okra | Mar 6 – Mar 20 | May 8 – May 22 | May 8 – May 22 | — |
| Basil | Mar 6 – Mar 20 | Apr 24 – May 8 | — | — |
| Peas | — | — | Mar 6 – Mar 27 | Jul 31 – Aug 21 |
| Spinach | — | — | Mar 6 – Mar 27 | Aug 28 – Sep 18 |
| Radishes | — | — | Mar 13 – Apr 24 | Sep 11 – Oct 2 |
| Cucumbers | Mar 20 – Mar 27 | May 1 – May 8 | Apr 24 – May 8 | Aug 7 – Aug 21 |
| Zucchini & Summer Squash | Mar 20 – Mar 27 | — | Apr 24 – May 8 | Aug 14 – Aug 28 |
| Winter Squash & Pumpkins | Mar 20 – Mar 27 | — | Apr 24 – May 8 | — |
| Melons & Watermelon | Mar 20 – Mar 27 | May 1 – May 15 | — | — |
| Carrots | — | — | Mar 27 – Apr 24 | Jul 31 – Aug 14 |
| Beets | — | — | Mar 27 – Apr 24 | Aug 14 – Aug 28 |
| Potatoes | — | — | Mar 27 – Apr 17 | — |
| Swiss Chard | — | — | Apr 3 – May 1 | Aug 14 – Aug 28 |
| Cilantro | — | — | Apr 3 – Apr 24 | Aug 28 – Sep 18 |
| Green Beans | — | — | Apr 24 – May 15 | Aug 7 – Aug 21 |
| Sweet Corn | — | — | Apr 24 – May 8 | — |
| Sweet Potatoes | — | May 1 – May 22 | — | — |
| Garlic | — | — | — | Oct 9 – Nov 13 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Monroe, WA weather station, 4 km away (elevation 121 ft (37 m)).
Frost dates near Monroe
- Snohomish Apr 17 · Oct 23
- Startup Apr 15 · Oct 25
- Duvall Apr 17 · Oct 23
- Woodinville Apr 17 · Oct 23
- Sultan Apr 15 · Oct 25
- Mill Creek Mar 9 · Nov 17
- Lake Stevens Mar 24 · Nov 2
- Bothell Mar 8 · Nov 23
- Everett Mar 9 · Nov 17
- Gold Bar Apr 15 · Oct 25
Frequently asked questions
When is the last frost in Monroe, WA?
The median last spring frost in Monroe, WA is April 17. There is still about a 10% chance of frost after May 7, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Monroe, WA?
The median first fall frost is October 23, with about a 10% chance of frost before October 7.
How long is the growing season in Monroe, WA?
About 189 days between the median last spring frost and first fall frost.
What planting zone is Monroe, WA?
Monroe, WA is in USDA hardiness zone 8b.