Hanover, WI frost dates
How Hanover compares
- In 8 years out of 10, the last spring frost in Hanover falls between April 13 and May 11, a 28-day window. The first fall frost falls between October 1 and October 27.
- The median last frost is 9 days earlier than the Wisconsin median of May 5.
- Its 172-day growing season is longer than 89% of the 749 Wisconsin places with a regular frost season (state median 155 days).
- The last frost is 5 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 148 nights a year at or below 32°F.
- Hanover shares its weather station with Janesville, WI, 12 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 13 |
| 50% (median) | April 26 |
| 10% (safe for tender plants) | May 11 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 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 Hanover, WI
Hanover, WI frost dates — last frost Apr 26, first frost Oct 15, zone 5b. whenisthelastfrost.com
When to plant vegetables in Hanover, WI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 1 – Feb 15 | Mar 29 – Apr 12 | — | — |
| Peppers | Feb 15 – Mar 1 | May 10 – May 24 | — | — |
| Eggplant | Feb 15 – Mar 1 | May 10 – May 24 | — | — |
| Tomatoes | Mar 1 – Mar 15 | May 3 – May 17 | — | — |
| Lettuce | Mar 1 – Mar 15 | Apr 5 – Apr 19 | Mar 29 – May 3 | Aug 20 – Sep 17 |
| Kale | Mar 1 – Mar 15 | Mar 29 – Apr 12 | Mar 29 – Apr 12 | Aug 6 – Aug 27 |
| Broccoli | Mar 1 – Mar 15 | Apr 12 – Apr 26 | — | Jul 9 – Jul 30 |
| Cabbage | Mar 1 – Mar 15 | Apr 5 – Apr 19 | — | Jul 9 – Jul 30 |
| Cauliflower | Mar 1 – Mar 15 | Apr 12 – Apr 26 | — | Jul 9 – Jul 30 |
| Okra | Mar 15 – Mar 29 | May 17 – May 31 | May 17 – May 31 | — |
| Basil | Mar 15 – Mar 29 | May 3 – May 17 | — | — |
| Peas | — | — | Mar 15 – Apr 5 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 15 – Apr 5 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 22 – May 3 | Sep 3 – Sep 24 |
| Cucumbers | Mar 29 – Apr 5 | May 10 – May 17 | May 3 – May 17 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Mar 29 – Apr 5 | — | May 3 – May 17 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Mar 29 – Apr 5 | — | May 3 – May 17 | — |
| Melons & Watermelon | Mar 29 – Apr 5 | May 10 – May 24 | — | — |
| Carrots | — | — | Apr 5 – May 3 | Jul 23 – Aug 6 |
| Beets | — | — | Apr 5 – May 3 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 5 – Apr 26 | — |
| Swiss Chard | — | — | Apr 12 – May 10 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 12 – May 3 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 3 – May 24 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 3 – May 17 | — |
| Sweet Potatoes | — | May 10 – May 31 | — | — |
| 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 Afton - Janesville Wwtp, WI weather station, 8 km away (elevation 761 ft (232 m)).
Frost dates near Hanover
- Footville Apr 26 · Oct 15
- Orfordville Apr 29 · Oct 12
- Afton Apr 26 · Oct 15
- Janesville Apr 26 · Oct 15
- Beloit May 1 · Oct 12
- Brodhead Apr 29 · Oct 12
- Evansville Apr 30 · Oct 11
- Milton Apr 28 · Oct 13
- Edgerton Apr 30 · Oct 11
- Albany Apr 29 · Oct 12
Frequently asked questions
When is the last frost in Hanover, WI?
The median last spring frost in Hanover, WI is April 26. There is still about a 10% chance of frost after May 11, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Hanover, WI?
The median first fall frost is October 15, with about a 10% chance of frost before October 1.
How long is the growing season in Hanover, WI?
About 172 days between the median last spring frost and first fall frost.
What planting zone is Hanover, WI?
Hanover, WI is in USDA hardiness zone 5b.