Clermont, IA frost dates
How Clermont compares
- In 8 years out of 10, the last spring frost in Clermont falls between April 18 and May 14, a 26-day window. The first fall frost falls between September 20 and October 17.
- 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 162 nights a year at or below 32°F.
- Compared with Waterloo, IA, 81 km away, the last frost here is 4 days later than there and the growing season is 11 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 18 |
| 50% (median) | May 1 |
| 10% (safe for tender plants) | May 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 20 |
| 50% (median) | October 3 |
| 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 Clermont, IA
Clermont, IA frost dates — last frost May 1, first frost Oct 3, zone 5a. whenisthelastfrost.com
When to plant vegetables in Clermont, 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 Postville, IA weather station, 12 km away (elevation 1,165 ft (355 m)).
Frost dates near Clermont
- Elgin May 1 · Oct 3
- Postville May 1 · Oct 3
- Castalia May 1 · Oct 3
- West Union May 4 · Oct 4
- Luana May 1 · Oct 3
- Ossian May 1 · Oct 3
- Wadena May 4 · Oct 4
- Monona May 1 · Oct 3
- Fayette May 4 · Oct 4
- Saint Lucas May 4 · Oct 4
Frequently asked questions
When is the last frost in Clermont, IA?
The median last spring frost in Clermont, IA is May 1. There is still about a 10% chance of frost after May 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Clermont, IA?
The median first fall frost is October 3, with about a 10% chance of frost before September 20.
How long is the growing season in Clermont, IA?
About 155 days between the median last spring frost and first fall frost.
What planting zone is Clermont, IA?
Clermont, IA is in USDA hardiness zone 5a.