Colfax, IA frost dates
Last spring frostApr 21median date
First fall frostOct 15median date
Growing season177 daysfrost-free
Hardiness zone5bZone 5b
How Colfax compares
- In 8 years out of 10, the last spring frost in Colfax falls between April 7 and May 5, a 28-day window. The first fall frost falls between September 30 and October 27.
- The median last frost is 7 days earlier than the Iowa median of Apr 28.
- Its 177-day growing season is longer than 84% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is 10 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 137 nights a year at or below 32°F.
- Compared with Des Moines, IA, 27 km away, the last frost here is 2 days earlier than there and the growing season is 2 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 7 |
| 50% (median) | April 21 |
| 10% (safe for tender plants) | May 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 30 |
| 50% (median) | October 15 |
| 90% (late) | October 27 |
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 Colfax, IA
Colfax, IA frost dates — last frost Apr 21, first frost Oct 15, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Jan 27 to Feb 10Transplant outside: Mar 24 to Apr 7
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 28 to May 12
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Sow outdoors: Mar 24 to Apr 28Plant for fall: Aug 20 to Sep 17
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 24 to Apr 7Sow outdoors: Mar 24 to Apr 7Plant for fall: Aug 6 to Aug 27
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 10 to Mar 24Transplant outside: May 12 to May 26Sow outdoors: May 12 to May 26
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 28 to May 12
Sow outdoors: Mar 10 to Mar 31Plant for fall: Jul 23 to Aug 13
Sow outdoors: Mar 10 to Mar 31Plant for fall: Aug 20 to Sep 10
Sow outdoors: Mar 17 to Apr 28Plant for fall: Sep 3 to Sep 24
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 12Sow outdoors: Apr 28 to May 12Plant for fall: Jul 30 to Aug 13
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 19
Sow outdoors: Mar 31 to Apr 28Plant for fall: Jul 23 to Aug 6
Sow outdoors: Mar 31 to Apr 28Plant for fall: Aug 6 to Aug 20
Sow outdoors: Mar 31 to Apr 21
Sow outdoors: Apr 7 to May 5Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 7 to Apr 28Plant for fall: Aug 20 to Sep 10
Sow outdoors: Apr 28 to May 19Plant for fall: Jul 30 to Aug 13
Sow outdoors: Apr 28 to May 12
Transplant outside: May 5 to May 26
Plant for fall: Oct 1 to Nov 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Colfax, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 27 – Feb 10 | Mar 24 – Apr 7 | — | — |
| Peppers | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Eggplant | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Tomatoes | Feb 24 – Mar 10 | Apr 28 – May 12 | — | — |
| Lettuce | Feb 24 – Mar 10 | Mar 31 – Apr 14 | Mar 24 – Apr 28 | Aug 20 – Sep 17 |
| Kale | Feb 24 – Mar 10 | Mar 24 – Apr 7 | Mar 24 – Apr 7 | Aug 6 – Aug 27 |
| Broccoli | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 9 – Jul 30 |
| Cabbage | Feb 24 – Mar 10 | Mar 31 – Apr 14 | — | Jul 9 – Jul 30 |
| Cauliflower | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 9 – Jul 30 |
| Okra | Mar 10 – Mar 24 | May 12 – May 26 | May 12 – May 26 | — |
| Basil | Mar 10 – Mar 24 | Apr 28 – May 12 | — | — |
| Peas | — | — | Mar 10 – Mar 31 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 10 – Mar 31 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 17 – Apr 28 | Sep 3 – Sep 24 |
| Cucumbers | Mar 24 – Mar 31 | May 5 – May 12 | Apr 28 – May 12 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Mar 24 – Mar 31 | — | Apr 28 – May 12 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Mar 24 – Mar 31 | — | Apr 28 – May 12 | — |
| Melons & Watermelon | Mar 24 – Mar 31 | May 5 – May 19 | — | — |
| Carrots | — | — | Mar 31 – Apr 28 | Jul 23 – Aug 6 |
| Beets | — | — | Mar 31 – Apr 28 | Aug 6 – Aug 20 |
| Potatoes | — | — | Mar 31 – Apr 21 | — |
| Swiss Chard | — | — | Apr 7 – May 5 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 7 – Apr 28 | Aug 20 – Sep 10 |
| Green Beans | — | — | Apr 28 – May 19 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | Apr 28 – May 12 | — |
| Sweet Potatoes | — | May 5 – May 26 | — | — |
| Garlic | — | — | — | Oct 1 – Nov 5 |
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 17 E, IA weather station, 14 km away (elevation 922 ft (281 m)).
Frost dates near Colfax
- Mitchellville Apr 21 · Oct 15
- Prairie City Apr 21 · Oct 15
- Ira Apr 22 · Oct 17
- Mingo Apr 22 · Oct 17
- Bondurant Apr 23 · Oct 15
- Baxter Apr 22 · Oct 17
- Newton Apr 22 · Oct 17
- Altoona Apr 23 · Oct 15
- Runnells Apr 21 · Oct 15
- Monroe Apr 21 · Oct 15
Frequently asked questions
When is the last frost in Colfax, IA?
The median last spring frost in Colfax, IA is April 21. There is still about a 10% chance of frost after May 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Colfax, IA?
The median first fall frost is October 15, with about a 10% chance of frost before September 30.
How long is the growing season in Colfax, IA?
About 177 days between the median last spring frost and first fall frost.
What planting zone is Colfax, IA?
Colfax, IA is in USDA hardiness zone 5b.