Whiting, IA frost dates
How Whiting compares
- In 8 years out of 10, the last spring frost in Whiting falls between April 19 and May 13, a 24-day window. The first fall frost falls between September 21 and October 18.
- The median last frost is 3 days later than the Iowa median of Apr 28.
- Its 155-day growing season is longer than 13% 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 151 nights a year at or below 32°F.
- Compared with Sioux City, IA, 40 km away, the last frost here is 2 days later than there and the growing season is 6 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | May 1 |
| 10% (safe for tender plants) | May 13 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 21 |
| 50% (median) | October 3 |
| 90% (late) | October 18 |
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 Whiting, IA
Whiting, IA frost dates — last frost May 1, first frost Oct 3, zone 5a. whenisthelastfrost.com
When to plant vegetables in Whiting, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 6 – Feb 20 | Apr 3 – Apr 17 | — | — |
| Peppers | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Eggplant | Feb 20 – Mar 6 | May 15 – May 29 | — | — |
| Tomatoes | Mar 6 – Mar 20 | May 8 – May 22 | — | — |
| Lettuce | Mar 6 – Mar 20 | Apr 10 – Apr 24 | Apr 3 – May 8 | Aug 8 – Sep 5 |
| Kale | Mar 6 – Mar 20 | Apr 3 – Apr 17 | Apr 3 – Apr 17 | Jul 25 – Aug 15 |
| Broccoli | Mar 6 – Mar 20 | Apr 17 – May 1 | — | Jun 27 – Jul 18 |
| Cabbage | Mar 6 – Mar 20 | Apr 10 – Apr 24 | — | Jun 27 – Jul 18 |
| Cauliflower | Mar 6 – Mar 20 | Apr 17 – May 1 | — | Jun 27 – Jul 18 |
| Okra | Mar 20 – Apr 3 | May 22 – Jun 5 | May 22 – Jun 5 | — |
| Basil | Mar 20 – Apr 3 | May 8 – May 22 | — | — |
| Peas | — | — | Mar 20 – Apr 10 | Jul 11 – Aug 1 |
| Spinach | — | — | Mar 20 – Apr 10 | Aug 8 – Aug 29 |
| Radishes | — | — | Mar 27 – May 8 | Aug 22 – Sep 12 |
| Cucumbers | Apr 3 – Apr 10 | May 15 – May 22 | May 8 – May 22 | Jul 18 – Aug 1 |
| Zucchini & Summer Squash | Apr 3 – Apr 10 | — | May 8 – May 22 | Jul 25 – Aug 8 |
| Winter Squash & Pumpkins | Apr 3 – Apr 10 | — | May 8 – May 22 | — |
| Melons & Watermelon | Apr 3 – Apr 10 | May 15 – May 29 | — | — |
| Carrots | — | — | Apr 10 – May 8 | Jul 11 – Jul 25 |
| Beets | — | — | Apr 10 – May 8 | Jul 25 – Aug 8 |
| Potatoes | — | — | Apr 10 – May 1 | — |
| Swiss Chard | — | — | Apr 17 – May 15 | Jul 25 – Aug 8 |
| Cilantro | — | — | Apr 17 – May 8 | Aug 8 – Aug 29 |
| Green Beans | — | — | May 8 – May 29 | Jul 18 – Aug 1 |
| Sweet Corn | — | — | May 8 – May 22 | — |
| Sweet Potatoes | — | May 15 – Jun 5 | — | — |
| Garlic | — | — | — | Sep 19 – Oct 24 |
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 Onawa 3nw, IA weather station, 10 km away (elevation 1,060 ft (323 m)).
Frost dates near Whiting
- Sloan Apr 29 · Oct 5
- Onawa May 1 · Oct 3
- Hornick May 1 · Oct 3
- Rodney May 3 · Oct 1
- Smithland May 3 · Oct 1
- Salix Apr 29 · Oct 5
- Climbing Hill Apr 29 · Oct 5
- Castana Apr 25 · Oct 12
- Blencoe May 1 · Oct 3
- Oto May 3 · Oct 1
Frequently asked questions
When is the last frost in Whiting, IA?
The median last spring frost in Whiting, IA is May 1. There is still about a 10% chance of frost after May 13, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Whiting, IA?
The median first fall frost is October 3, with about a 10% chance of frost before September 21.
How long is the growing season in Whiting, IA?
About 155 days between the median last spring frost and first fall frost.
What planting zone is Whiting, IA?
Whiting, IA is in USDA hardiness zone 5a.