Frost dates for 51566 — Red Oak, IA
Last spring frostApr 24median date
First fall frostOct 13median date
Growing season172 daysfrost-free
Hardiness zone5bZone 5b
How Red Oak compares
- In 8 years out of 10, the last spring frost in Red Oak falls between April 10 and May 8, a 28-day window. The first fall frost falls between September 26 and October 25.
- The median last frost is 4 days earlier than the Iowa median of Apr 28.
- Its 172-day growing season is longer than 76% of the 934 Iowa places with a regular frost season (state median 165 days).
- The last frost is 7 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 142 nights a year at or below 32°F.
- Compared with Council Bluffs, IA, 59 km away, the last frost here is 6 days later than there and the growing season is 14 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 10 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 8 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 13 |
| 90% (late) | October 25 |
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 Red Oak, IA
Frost dates for 51566 — Red Oak, IA — last frost Apr 24, first frost Oct 13, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Jan 30 to Feb 13Transplant outside: Mar 27 to Apr 10
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Sow outdoors: Mar 27 to May 1Plant for fall: Aug 18 to Sep 15
Start indoors: Feb 27 to Mar 13Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 27 to Apr 10Plant for fall: Aug 4 to Aug 25
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 7 to Jul 28
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 7 to Jul 28
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 13 to Apr 3Plant for fall: Jul 21 to Aug 11
Sow outdoors: Mar 13 to Apr 3Plant for fall: Aug 18 to Sep 8
Sow outdoors: Mar 20 to May 1Plant for fall: Sep 1 to Sep 22
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 15Sow outdoors: May 1 to May 15Plant for fall: Jul 28 to Aug 11
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15Plant for fall: Aug 4 to Aug 18
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 22
Sow outdoors: Apr 3 to May 1Plant for fall: Jul 21 to Aug 4
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 3 to Apr 24
Sow outdoors: Apr 10 to May 8Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 10 to May 1Plant for fall: Aug 18 to Sep 8
Sow outdoors: May 1 to May 22Plant for fall: Jul 28 to Aug 11
Sow outdoors: May 1 to May 15
Transplant outside: May 8 to May 29
Plant for fall: Sep 29 to Nov 3
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Red Oak, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Peppers | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Tomatoes | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Lettuce | Feb 27 – Mar 13 | Apr 3 – Apr 17 | Mar 27 – May 1 | Aug 18 – Sep 15 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 4 – Aug 25 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 7 – Jul 28 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 7 – Jul 28 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 7 – Jul 28 |
| Okra | Mar 13 – Mar 27 | May 15 – May 29 | May 15 – May 29 | — |
| Basil | Mar 13 – Mar 27 | May 1 – May 15 | — | — |
| Peas | — | — | Mar 13 – Apr 3 | Jul 21 – Aug 11 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 18 – Sep 8 |
| Radishes | — | — | Mar 20 – May 1 | Sep 1 – Sep 22 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Jul 28 – Aug 11 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 4 – Aug 18 |
| Winter Squash & Pumpkins | Mar 27 – Apr 3 | — | May 1 – May 15 | — |
| Melons & Watermelon | Mar 27 – Apr 3 | May 8 – May 22 | — | — |
| Carrots | — | — | Apr 3 – May 1 | Jul 21 – Aug 4 |
| Beets | — | — | Apr 3 – May 1 | Aug 4 – Aug 18 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 4 – Aug 18 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 18 – Sep 8 |
| Green Beans | — | — | May 1 – May 22 | Jul 28 – Aug 11 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| Garlic | — | — | — | Sep 29 – Nov 3 |
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 Red Oak, IA weather station, about 1 km away (elevation 1,040 ft (317 m)).
ZIP codes in Red Oak: 51566 51591
Frost dates near Red Oak
- Stanton Apr 24 · Oct 13
- Elliott Apr 24 · Oct 13
- Emerson Apr 24 · Oct 13
- Essex Apr 20 · Oct 17
- Villisca Apr 27 · Oct 12
- Hastings Apr 24 · Oct 13
- Henderson Apr 23 · Oct 14
- Imogene Apr 20 · Oct 17
Frequently asked questions
When is the last frost in Red Oak, IA?
The median last spring frost in Red Oak, IA is April 24. There is still about a 10% chance of frost after May 8, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Red Oak, IA?
The median first fall frost is October 13, with about a 10% chance of frost before September 26.
How long is the growing season in Red Oak, IA?
About 172 days between the median last spring frost and first fall frost.
What planting zone is Red Oak, IA?
Red Oak, IA is in USDA hardiness zone 5b.