Mapleton, IA frost dates
Last spring frostMay 3median date
First fall frostOct 1median date
Growing season151 daysfrost-free
Hardiness zone5aZone 5a
How Mapleton compares
- In 8 years out of 10, the last spring frost in Mapleton falls between April 21 and May 16, a 25-day window. The first fall frost falls between September 19 and October 17.
- The median last frost is 5 days later than the Iowa median of Apr 28.
- Its 151-day growing season is longer than 3% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is typical for zone 5a, where the median is May 3.
- The weather station records an average of 156 nights a year at or below 32°F.
- Compared with Sioux City, IA, 61 km away, the last frost here is 4 days later than there and the growing season is 10 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 21 |
| 50% (median) | May 3 |
| 10% (safe for tender plants) | May 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 19 |
| 50% (median) | October 1 |
| 90% (late) | October 17 |
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 Mapleton, IA
Mapleton, IA frost dates — last frost May 3, first frost Oct 1, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 8 to Feb 22Transplant outside: Apr 5 to Apr 19
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Mar 8 to Mar 22Transplant outside: May 10 to May 24
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Sow outdoors: Apr 5 to May 10Plant for fall: Aug 6 to Sep 3
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 5 to Apr 19Sow outdoors: Apr 5 to Apr 19Plant for fall: Jul 23 to Aug 13
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jun 25 to Jul 16
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Plant for fall: Jun 25 to Jul 16
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jun 25 to Jul 16
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7Sow outdoors: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: May 10 to May 24
Sow outdoors: Mar 22 to Apr 12Plant for fall: Jul 9 to Jul 30
Sow outdoors: Mar 22 to Apr 12Plant for fall: Aug 6 to Aug 27
Sow outdoors: Mar 29 to May 10Plant for fall: Aug 20 to Sep 10
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 24Sow outdoors: May 10 to May 24Plant for fall: Jul 16 to Jul 30
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24Plant for fall: Jul 23 to Aug 6
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 31
Sow outdoors: Apr 12 to May 10Plant for fall: Jul 9 to Jul 23
Sow outdoors: Apr 12 to May 10Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 12 to May 3
Sow outdoors: Apr 19 to May 17Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 19 to May 10Plant for fall: Aug 6 to Aug 27
Sow outdoors: May 10 to May 31Plant for fall: Jul 16 to Jul 30
Sow outdoors: May 10 to May 24
Transplant outside: May 17 to Jun 7
Plant for fall: Sep 17 to Oct 22
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Mapleton, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Peppers | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Tomatoes | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Lettuce | Mar 8 – Mar 22 | Apr 12 – Apr 26 | Apr 5 – May 10 | Aug 6 – Sep 3 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 19 | Apr 5 – Apr 19 | Jul 23 – Aug 13 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jun 25 – Jul 16 |
| Cabbage | Mar 8 – Mar 22 | Apr 12 – Apr 26 | — | Jun 25 – Jul 16 |
| Cauliflower | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jun 25 – Jul 16 |
| Okra | Mar 22 – Apr 5 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Basil | Mar 22 – Apr 5 | May 10 – May 24 | — | — |
| Peas | — | — | Mar 22 – Apr 12 | Jul 9 – Jul 30 |
| Spinach | — | — | Mar 22 – Apr 12 | Aug 6 – Aug 27 |
| Radishes | — | — | Mar 29 – May 10 | Aug 20 – Sep 10 |
| Cucumbers | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 24 | Jul 16 – Jul 30 |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | — | May 10 – May 24 | Jul 23 – Aug 6 |
| Winter Squash & Pumpkins | Apr 5 – Apr 12 | — | May 10 – May 24 | — |
| Melons & Watermelon | Apr 5 – Apr 12 | May 17 – May 31 | — | — |
| Carrots | — | — | Apr 12 – May 10 | Jul 9 – Jul 23 |
| Beets | — | — | Apr 12 – May 10 | Jul 23 – Aug 6 |
| Potatoes | — | — | Apr 12 – May 3 | — |
| Swiss Chard | — | — | Apr 19 – May 17 | Jul 23 – Aug 6 |
| Cilantro | — | — | Apr 19 – May 10 | Aug 6 – Aug 27 |
| Green Beans | — | — | May 10 – May 31 | Jul 16 – Jul 30 |
| Sweet Corn | — | — | May 10 – May 24 | — |
| Sweet Potatoes | — | May 17 – Jun 7 | — | — |
| Garlic | — | — | — | Sep 17 – Oct 22 |
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 Mapleton No.2, IA weather station, about 1 km away (elevation 1,201 ft (366 m)).
Frost dates near Mapleton
- Ute Apr 25 · Oct 12
- Oto May 3 · Oct 1
- Danbury May 3 · Oct 1
- Castana Apr 25 · Oct 12
- Smithland May 3 · Oct 1
- Rodney May 3 · Oct 1
- Ricketts May 3 · Oct 1
- Soldier Apr 25 · Oct 12
- Charter Oak May 3 · Oct 1
- Battle Creek May 1 · Oct 1
Frequently asked questions
When is the last frost in Mapleton, IA?
The median last spring frost in Mapleton, IA is May 3. There is still about a 10% chance of frost after May 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mapleton, IA?
The median first fall frost is October 1, with about a 10% chance of frost before September 19.
How long is the growing season in Mapleton, IA?
About 151 days between the median last spring frost and first fall frost.
What planting zone is Mapleton, IA?
Mapleton, IA is in USDA hardiness zone 5a.