Grimes, IA frost dates
Last spring frostApr 19median date
First fall frostOct 18median date
Growing season182 daysfrost-free
Hardiness zone5bZone 5b
How Grimes compares
- In 8 years out of 10, the last spring frost in Grimes falls between April 5 and May 3, a 28-day window. The first fall frost falls between October 1 and October 30.
- The median last frost is 9 days earlier than the Iowa median of Apr 28.
- Its 182-day growing season is longer than 90% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is 12 days earlier than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 135 nights a year at or below 32°F.
- Compared with West Des Moines, IA, 14 km away, the last frost here is 1 day later than there and the growing season is 3 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 5 |
| 50% (median) | April 19 |
| 10% (safe for tender plants) | May 3 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 18 |
| 90% (late) | October 30 |
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 Grimes, IA
Grimes, IA frost dates — last frost Apr 19, first frost Oct 18, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Jan 25 to Feb 8Transplant outside: Mar 22 to Apr 5
Start indoors: Feb 8 to Feb 22Transplant outside: May 3 to May 17
Start indoors: Feb 8 to Feb 22Transplant outside: May 3 to May 17
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 26 to May 10
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 29 to Apr 12Sow outdoors: Mar 22 to Apr 26Plant for fall: Aug 23 to Sep 20
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 22 to Apr 5Sow outdoors: Mar 22 to Apr 5Plant for fall: Aug 9 to Aug 30
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 5 to Apr 19Plant for fall: Jul 12 to Aug 2
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 29 to Apr 12Plant for fall: Jul 12 to Aug 2
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 5 to Apr 19Plant for fall: Jul 12 to Aug 2
Start indoors: Mar 8 to Mar 22Transplant outside: May 10 to May 24Sow outdoors: May 10 to May 24
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 26 to May 10
Sow outdoors: Mar 8 to Mar 29Plant for fall: Jul 26 to Aug 16
Sow outdoors: Mar 8 to Mar 29Plant for fall: Aug 23 to Sep 13
Sow outdoors: Mar 15 to Apr 26Plant for fall: Sep 6 to Sep 27
Start indoors: Mar 22 to Mar 29Transplant outside: May 3 to May 10Sow outdoors: Apr 26 to May 10Plant for fall: Aug 2 to Aug 16
Start indoors: Mar 22 to Mar 29Sow outdoors: Apr 26 to May 10Plant for fall: Aug 9 to Aug 23
Start indoors: Mar 22 to Mar 29Sow outdoors: Apr 26 to May 10
Start indoors: Mar 22 to Mar 29Transplant outside: May 3 to May 17
Sow outdoors: Mar 29 to Apr 26Plant for fall: Jul 26 to Aug 9
Sow outdoors: Mar 29 to Apr 26Plant for fall: Aug 9 to Aug 23
Sow outdoors: Mar 29 to Apr 19
Sow outdoors: Apr 5 to May 3Plant for fall: Aug 9 to Aug 23
Sow outdoors: Apr 5 to Apr 26Plant for fall: Aug 23 to Sep 13
Sow outdoors: Apr 26 to May 17Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 26 to May 10
Transplant outside: May 3 to May 24
Plant for fall: Oct 4 to Nov 8
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Grimes, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 25 – Feb 8 | Mar 22 – Apr 5 | — | — |
| Peppers | Feb 8 – Feb 22 | May 3 – May 17 | — | — |
| Eggplant | Feb 8 – Feb 22 | May 3 – May 17 | — | — |
| Tomatoes | Feb 22 – Mar 8 | Apr 26 – May 10 | — | — |
| Lettuce | Feb 22 – Mar 8 | Mar 29 – Apr 12 | Mar 22 – Apr 26 | Aug 23 – Sep 20 |
| Kale | Feb 22 – Mar 8 | Mar 22 – Apr 5 | Mar 22 – Apr 5 | Aug 9 – Aug 30 |
| Broccoli | Feb 22 – Mar 8 | Apr 5 – Apr 19 | — | Jul 12 – Aug 2 |
| Cabbage | Feb 22 – Mar 8 | Mar 29 – Apr 12 | — | Jul 12 – Aug 2 |
| Cauliflower | Feb 22 – Mar 8 | Apr 5 – Apr 19 | — | Jul 12 – Aug 2 |
| Okra | Mar 8 – Mar 22 | May 10 – May 24 | May 10 – May 24 | — |
| Basil | Mar 8 – Mar 22 | Apr 26 – May 10 | — | — |
| Peas | — | — | Mar 8 – Mar 29 | Jul 26 – Aug 16 |
| Spinach | — | — | Mar 8 – Mar 29 | Aug 23 – Sep 13 |
| Radishes | — | — | Mar 15 – Apr 26 | Sep 6 – Sep 27 |
| Cucumbers | Mar 22 – Mar 29 | May 3 – May 10 | Apr 26 – May 10 | Aug 2 – Aug 16 |
| Zucchini & Summer Squash | Mar 22 – Mar 29 | — | Apr 26 – May 10 | Aug 9 – Aug 23 |
| Winter Squash & Pumpkins | Mar 22 – Mar 29 | — | Apr 26 – May 10 | — |
| Melons & Watermelon | Mar 22 – Mar 29 | May 3 – May 17 | — | — |
| Carrots | — | — | Mar 29 – Apr 26 | Jul 26 – Aug 9 |
| Beets | — | — | Mar 29 – Apr 26 | Aug 9 – Aug 23 |
| Potatoes | — | — | Mar 29 – Apr 19 | — |
| Swiss Chard | — | — | Apr 5 – May 3 | Aug 9 – Aug 23 |
| Cilantro | — | — | Apr 5 – Apr 26 | Aug 23 – Sep 13 |
| Green Beans | — | — | Apr 26 – May 17 | Aug 2 – Aug 16 |
| Sweet Corn | — | — | Apr 26 – May 10 | — |
| Sweet Potatoes | — | May 3 – May 24 | — | — |
| Garlic | — | — | — | Oct 4 – Nov 8 |
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 Des Moines Wsfo-Johnston, IA weather station, 6 km away (elevation 958 ft (292 m)).
Frost dates near Grimes
- Johnston Apr 19 · Oct 18
- Granger Apr 19 · Oct 18
- Urbandale Apr 19 · Oct 18
- Polk City Apr 19 · Oct 18
- Clive Apr 18 · Oct 20
- Windsor Heights Apr 18 · Oct 20
- Waukee Apr 18 · Oct 20
- West Des Moines Apr 18 · Oct 20
- Ankeny Apr 23 · Oct 15
- Dallas Center Apr 25 · Oct 10
Frequently asked questions
When is the last frost in Grimes, IA?
The median last spring frost in Grimes, IA is April 19. There is still about a 10% chance of frost after May 3, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Grimes, IA?
The median first fall frost is October 18, with about a 10% chance of frost before October 1.
How long is the growing season in Grimes, IA?
About 182 days between the median last spring frost and first fall frost.
What planting zone is Grimes, IA?
Grimes, IA is in USDA hardiness zone 5b.