Calumet, IA frost dates
Last spring frostApr 29median date
First fall frostOct 10median date
Growing season164 daysfrost-free
Hardiness zone5aZone 5a
How Calumet compares
- In 8 years out of 10, the last spring frost in Calumet falls between April 13 and May 11, a 28-day window. The first fall frost falls between September 26 and October 23.
- The median last frost is 1 day later than the Iowa median of Apr 28.
- Its 164-day growing season is longer than 43% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is 4 days earlier than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 153 nights a year at or below 32°F.
- Compared with Sioux City, IA, 86 km away, the last frost here is the same as there and the growing season is 3 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 13 |
| 50% (median) | April 29 |
| 10% (safe for tender plants) | May 11 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 10 |
| 90% (late) | October 23 |
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 Calumet, IA
Calumet, IA frost dates — last frost Apr 29, first frost Oct 10, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 4 to Feb 18Transplant outside: Apr 1 to Apr 15
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Mar 4 to Mar 18Transplant outside: May 6 to May 20
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Sow outdoors: Apr 1 to May 6Plant for fall: Aug 15 to Sep 12
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 1 to Apr 15Sow outdoors: Apr 1 to Apr 15Plant for fall: Aug 1 to Aug 22
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jul 4 to Jul 25
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 4 to Jul 25
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jul 4 to Jul 25
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3Sow outdoors: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Mar 18 to Apr 8Plant for fall: Jul 18 to Aug 8
Sow outdoors: Mar 18 to Apr 8Plant for fall: Aug 15 to Sep 5
Sow outdoors: Mar 25 to May 6Plant for fall: Aug 29 to Sep 19
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 20Sow outdoors: May 6 to May 20Plant for fall: Jul 25 to Aug 8
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20Plant for fall: Aug 1 to Aug 15
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 27
Sow outdoors: Apr 8 to May 6Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 8 to May 6Plant for fall: Aug 1 to Aug 15
Sow outdoors: Apr 8 to Apr 29
Sow outdoors: Apr 15 to May 13Plant for fall: Aug 1 to Aug 15
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 15 to Sep 5
Sow outdoors: May 6 to May 27Plant for fall: Jul 25 to Aug 8
Sow outdoors: May 6 to May 20
Transplant outside: May 13 to Jun 3
Plant for fall: Sep 26 to Oct 31
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Calumet, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 4 – Feb 18 | Apr 1 – Apr 15 | — | — |
| Peppers | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Eggplant | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Tomatoes | Mar 4 – Mar 18 | May 6 – May 20 | — | — |
| Lettuce | Mar 4 – Mar 18 | Apr 8 – Apr 22 | Apr 1 – May 6 | Aug 15 – Sep 12 |
| Kale | Mar 4 – Mar 18 | Apr 1 – Apr 15 | Apr 1 – Apr 15 | Aug 1 – Aug 22 |
| Broccoli | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jul 4 – Jul 25 |
| Cabbage | Mar 4 – Mar 18 | Apr 8 – Apr 22 | — | Jul 4 – Jul 25 |
| Cauliflower | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jul 4 – Jul 25 |
| Okra | Mar 18 – Apr 1 | May 20 – Jun 3 | May 20 – Jun 3 | — |
| Basil | Mar 18 – Apr 1 | May 6 – May 20 | — | — |
| Peas | — | — | Mar 18 – Apr 8 | Jul 18 – Aug 8 |
| Spinach | — | — | Mar 18 – Apr 8 | Aug 15 – Sep 5 |
| Radishes | — | — | Mar 25 – May 6 | Aug 29 – Sep 19 |
| Cucumbers | Apr 1 – Apr 8 | May 13 – May 20 | May 6 – May 20 | Jul 25 – Aug 8 |
| Zucchini & Summer Squash | Apr 1 – Apr 8 | — | May 6 – May 20 | Aug 1 – Aug 15 |
| Winter Squash & Pumpkins | Apr 1 – Apr 8 | — | May 6 – May 20 | — |
| Melons & Watermelon | Apr 1 – Apr 8 | May 13 – May 27 | — | — |
| Carrots | — | — | Apr 8 – May 6 | Jul 18 – Aug 1 |
| Beets | — | — | Apr 8 – May 6 | Aug 1 – Aug 15 |
| Potatoes | — | — | Apr 8 – Apr 29 | — |
| Swiss Chard | — | — | Apr 15 – May 13 | Aug 1 – Aug 15 |
| Cilantro | — | — | Apr 15 – May 6 | Aug 15 – Sep 5 |
| Green Beans | — | — | May 6 – May 27 | Jul 25 – Aug 8 |
| Sweet Corn | — | — | May 6 – May 20 | — |
| Sweet Potatoes | — | May 13 – Jun 3 | — | — |
| Garlic | — | — | — | Sep 26 – Oct 31 |
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 Primghar, IA weather station, 17 km away (elevation 1,519 ft (463 m)).
Frost dates near Calumet
- Sutherland Apr 29 · Oct 10
- Larrabee May 4 · Oct 4
- Paullina Apr 29 · Oct 10
- Primghar Apr 29 · Oct 10
- Peterson Apr 30 · Oct 5
- Meriden May 4 · Oct 4
- Cleghorn May 4 · Oct 4
- Cherokee May 4 · Oct 4
- Marcus May 4 · Oct 4
- Archer May 1 · Oct 7
Frequently asked questions
When is the last frost in Calumet, IA?
The median last spring frost in Calumet, IA is April 29. There is still about a 10% chance of frost after May 11, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Calumet, IA?
The median first fall frost is October 10, with about a 10% chance of frost before September 26.
How long is the growing season in Calumet, IA?
About 164 days between the median last spring frost and first fall frost.
What planting zone is Calumet, IA?
Calumet, IA is in USDA hardiness zone 5a.