Last frost date in Wauwatosa, WI
The average last frost in Wauwatosa is April 26. By May 12 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about October 18, which leaves 173 frost-free days. An early freeze before October 2 happens one year in ten.
- Safe after (10% risk)
- May 12
- Average first frost
- Oct 18
- Frost-free season
- 173 days
- Hard freeze (28°F) ends
- Apr 14
No frost in the next 7 nights
Later than usual: the average first frost here is October 18.
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2249°
- FriOct 2350°
- SatOct 2453°
- SunOct 2551°
- MonOct 2647°
- TueOct 2744°
- WedOct 2844°
Planting calendar for Wauwatosa
Windows count forward or back from the average frost dates above. Click a crop for dates across Wisconsin.
Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 12 | Apr 26 | May 12 | Oct 2 | Oct 18 | Nov 1 |
| Hard freeze, 28°F | Apr 1 | Apr 14 | Apr 30 | Oct 13 | Oct 30 | Nov 11 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Mount Mary College (USC00475474) sits 0.7 miles from the center of Wauwatosa at 715 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Wauwatosa, WI?
The average last frost date in Wauwatosa is April 26, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 12.
When is the first frost in Wauwatosa?
The first frost in fall usually comes around October 18. One year in ten it arrives before October 2.
How long is the growing season in Wauwatosa?
About 173 days between the average last and first frost.
When should I plant tomatoes in Wauwatosa?
Plant tomato seedlings outside from May 3 to May 17. Start seeds indoors six to eight weeks earlier.
Nearby in Wisconsin
- MilwaukeeApr 26
- West AllisApr 26
- BrookfieldApr 30
- GreenfieldMay 3
- New BerlinMay 3
- Menomonee FallsMay 6
- MequonMay 6
- WaukeshaMay 1
- FranklinMay 3
- GermantownMay 6
- South MilwaukeeApr 22
- MuskegoMay 3