Ollie, IA frost dates
How Ollie compares
- In 8 years out of 10, the last spring frost in Ollie falls between April 9 and May 9, a 30-day window. The first fall frost falls between September 30 and October 27.
- The median last frost is 4 days earlier than the Iowa median of Apr 28.
- Its 174-day growing season is longer than 78% 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 Iowa City, IA, 69 km away, the last frost here is 3 days later than there and the growing season is 6 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 9 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 9 |
| 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 Ollie, IA
Ollie, IA frost dates — last frost Apr 24, first frost Oct 15, zone 5b. whenisthelastfrost.com
When to plant vegetables in Ollie, 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 20 – Sep 17 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 6 – Aug 27 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 9 – Jul 30 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| 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 23 – Aug 13 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 20 – May 1 | Sep 3 – Sep 24 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 6 – Aug 20 |
| 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 23 – Aug 6 |
| Beets | — | — | Apr 3 – May 1 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 1 – May 22 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| 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 Sigourney, IA weather station, 17 km away (elevation 732 ft (223 m)).
Frost dates near Ollie
- Packwood Apr 27 · Oct 12
- Martinsburg Apr 24 · Oct 15
- Richland Apr 27 · Oct 12
- Hedrick Apr 23 · Oct 14
- Sigourney Apr 24 · Oct 15
- Hayesville Apr 24 · Oct 15
- Harper Apr 24 · Oct 15
- Delta Apr 24 · Oct 15
- Keota Apr 24 · Oct 15
- Batavia Apr 27 · Oct 12
Frequently asked questions
When is the last frost in Ollie, IA?
The median last spring frost in Ollie, IA is April 24. There is still about a 10% chance of frost after May 9, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ollie, 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 Ollie, IA?
About 174 days between the median last spring frost and first fall frost.
What planting zone is Ollie, IA?
Ollie, IA is in USDA hardiness zone 5b.