Hamlin, IA frost dates
Last spring frostMay 2median date
First fall frostOct 3median date
Growing season154 daysfrost-free
Hardiness zone5aZone 5a
How Hamlin compares
- In 8 years out of 10, the last spring frost in Hamlin falls between April 19 and May 15, a 26-day window. The first fall frost falls between September 19 and October 17.
- The median last frost is 4 days later than the Iowa median of Apr 28.
- Its 154-day growing season is longer than 10% 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 160 nights a year at or below 32°F.
- Compared with Council Bluffs, IA, 90 km away, the last frost here is 14 days later than there and the growing season is 32 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | May 2 |
| 10% (safe for tender plants) | May 15 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 19 |
| 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 Hamlin, IA
Hamlin, IA frost dates — last frost May 2, first frost Oct 3, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Feb 7 to Feb 21Transplant outside: Apr 4 to Apr 18
Start indoors: Feb 21 to Mar 7Transplant outside: May 16 to May 30
Start indoors: Feb 21 to Mar 7Transplant outside: May 16 to May 30
Start indoors: Mar 7 to Mar 21Transplant outside: May 9 to May 23
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 11 to Apr 25Sow outdoors: Apr 4 to May 9Plant for fall: Aug 8 to Sep 5
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 4 to Apr 18Sow outdoors: Apr 4 to Apr 18Plant for fall: Jul 25 to Aug 15
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 18 to May 2Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 11 to Apr 25Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 7 to Mar 21Transplant outside: Apr 18 to May 2Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 21 to Apr 4Transplant outside: May 23 to Jun 6Sow outdoors: May 23 to Jun 6
Start indoors: Mar 21 to Apr 4Transplant outside: May 9 to May 23
Sow outdoors: Mar 21 to Apr 11Plant for fall: Jul 11 to Aug 1
Sow outdoors: Mar 21 to Apr 11Plant for fall: Aug 8 to Aug 29
Sow outdoors: Mar 28 to May 9Plant for fall: Aug 22 to Sep 12
Start indoors: Apr 4 to Apr 11Transplant outside: May 16 to May 23Sow outdoors: May 9 to May 23Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 4 to Apr 11Sow outdoors: May 9 to May 23Plant for fall: Jul 25 to Aug 8
Start indoors: Apr 4 to Apr 11Sow outdoors: May 9 to May 23
Start indoors: Apr 4 to Apr 11Transplant outside: May 16 to May 30
Sow outdoors: Apr 11 to May 9Plant for fall: Jul 11 to Jul 25
Sow outdoors: Apr 11 to May 9Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 11 to May 2
Sow outdoors: Apr 18 to May 16Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 18 to May 9Plant for fall: Aug 8 to Aug 29
Sow outdoors: May 9 to May 30Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 9 to May 23
Transplant outside: May 16 to Jun 6
Plant for fall: Sep 19 to Oct 24
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Hamlin, IA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 7 – Feb 21 | Apr 4 – Apr 18 | — | — |
| Peppers | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Eggplant | Feb 21 – Mar 7 | May 16 – May 30 | — | — |
| Tomatoes | Mar 7 – Mar 21 | May 9 – May 23 | — | — |
| Lettuce | Mar 7 – Mar 21 | Apr 11 – Apr 25 | Apr 4 – May 9 | Aug 8 – Sep 5 |
| Kale | Mar 7 – Mar 21 | Apr 4 – Apr 18 | Apr 4 – Apr 18 | Jul 25 – Aug 15 |
| Broccoli | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jun 27 – Jul 18 |
| Cabbage | Mar 7 – Mar 21 | Apr 11 – Apr 25 | — | Jun 27 – Jul 18 |
| Cauliflower | Mar 7 – Mar 21 | Apr 18 – May 2 | — | Jun 27 – Jul 18 |
| Okra | Mar 21 – Apr 4 | May 23 – Jun 6 | May 23 – Jun 6 | — |
| Basil | Mar 21 – Apr 4 | May 9 – May 23 | — | — |
| Peas | — | — | Mar 21 – Apr 11 | Jul 11 – Aug 1 |
| Spinach | — | — | Mar 21 – Apr 11 | Aug 8 – Aug 29 |
| Radishes | — | — | Mar 28 – May 9 | Aug 22 – Sep 12 |
| Cucumbers | Apr 4 – Apr 11 | May 16 – May 23 | May 9 – May 23 | Jul 18 – Aug 1 |
| Zucchini & Summer Squash | Apr 4 – Apr 11 | — | May 9 – May 23 | Jul 25 – Aug 8 |
| Winter Squash & Pumpkins | Apr 4 – Apr 11 | — | May 9 – May 23 | — |
| Melons & Watermelon | Apr 4 – Apr 11 | May 16 – May 30 | — | — |
| Carrots | — | — | Apr 11 – May 9 | Jul 11 – Jul 25 |
| Beets | — | — | Apr 11 – May 9 | Jul 25 – Aug 8 |
| Potatoes | — | — | Apr 11 – May 2 | — |
| Swiss Chard | — | — | Apr 18 – May 16 | Jul 25 – Aug 8 |
| Cilantro | — | — | Apr 18 – May 9 | Aug 8 – Aug 29 |
| Green Beans | — | — | May 9 – May 30 | Jul 18 – Aug 1 |
| Sweet Corn | — | — | May 9 – May 23 | — |
| Sweet Potatoes | — | May 16 – Jun 6 | — | — |
| 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 Audubon, IA weather station, 6 km away (elevation 1,280 ft (390 m)).
Frost dates near Hamlin
- Audubon May 2 · Oct 3
- Exira May 2 · Oct 3
- Kimballton May 2 · Oct 3
- Brayton Apr 30 · Oct 2
- Elk Horn May 2 · Oct 3
- Gray May 2 · Oct 3
- Anita Apr 30 · Oct 2
- Marne Apr 30 · Oct 2
- Irwin Apr 27 · Oct 9
- Adair May 2 · Oct 3
Frequently asked questions
When is the last frost in Hamlin, IA?
The median last spring frost in Hamlin, IA is May 2. There is still about a 10% chance of frost after May 15, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Hamlin, IA?
The median first fall frost is October 3, with about a 10% chance of frost before September 19.
How long is the growing season in Hamlin, IA?
About 154 days between the median last spring frost and first fall frost.
What planting zone is Hamlin, IA?
Hamlin, IA is in USDA hardiness zone 5a.