USDA Hardiness Zone 6a
Frost Dates for 53207 — Milwaukee, Wisconsin
NOAA 1991–2020 normals from Milwaukee Mitchell Airport, WI (670 ft), 2 miles south.
Updated
In Milwaukee, the last spring frost (32°F) is around April 19 in half of years and has passed by May 2 in nine years out of ten. The first fall frost comes around October 29, as early as October 15 one year in ten, leaving a typical freeze-free season of 192 days (NOAA, Milwaukee Mitchell Airport, WI).
- Last spring frost
- April 19
- First fall frost
- October 29
- Growing season
- 192 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- November 13
- Last snow
- April 13
- Winters with snow
- 100%
- Snow per year
- 48.7"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Milwaukee
Half of springs at Milwaukee Mitchell Airport, WI see their last 32°F night by April 19; only one in ten is past it by April 6, and one in ten still has one after May 2. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 29 20%, and after May 2 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 84% of the 182 Wisconsin stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 29 in half of years, as early as October 15 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 10 days later, around November 8; in spring the one-in-ten date for 28°F is April 20, 12 days before the 32°F one. The freeze-free season lasts 192 days in a typical year, the longest of the 182 Wisconsin stations; it reaches 211 days one year in ten and falls short of 173 one year in ten. On average 123 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about May 1, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 4 and March 8.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 18 | Apr 23 | Apr 27 | Apr 30 | May 1 | May 4 | May 7 | May 10 | May 15 |
| 32°F | Apr 6 | Apr 9 | Apr 13 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 29 | May 2 |
| 28°F | Mar 24 | Mar 30 | Apr 2 | Apr 4 | Apr 6 | Apr 9 | Apr 11 | Apr 15 | Apr 20 |
| 24°F | Mar 11 | Mar 17 | Mar 21 | Mar 25 | Mar 28 | Mar 31 | Apr 2 | Apr 5 | Apr 9 |
| 20°F | Mar 2 | Mar 7 | Mar 10 | Mar 14 | Mar 16 | Mar 19 | Mar 23 | Mar 27 | Mar 30 |
| 16°F | Feb 22 | Feb 27 | Mar 3 | Mar 5 | Mar 8 | Mar 11 | Mar 14 | Mar 18 | Mar 23 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 5 | Oct 9 | Oct 13 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 26 | Oct 30 |
| 32°F | Oct 15 | Oct 20 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 2 | Nov 6 | Nov 10 |
| 28°F | Oct 27 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
| 24°F | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 20 | Nov 24 | Nov 27 | Dec 1 |
| 20°F | Nov 9 | Nov 15 | Nov 19 | Nov 24 | Nov 27 | Nov 29 | Dec 2 | Dec 6 | Dec 13 |
| 16°F | Nov 18 | Nov 25 | Nov 29 | Dec 1 | Dec 4 | Dec 8 | Dec 12 | Dec 17 | Dec 22 |
Freeze probabilities 1991–2020 at Milwaukee Mitchell Airport, WI, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 53207 →Compare Milwaukee with another place →
Weather by month in Milwaukee
July is the warmest month at Milwaukee Mitchell Airport, WI, averaging 82°F by day and 65°F at night; January is the coldest at 31°F and 17°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 12% of years.
Warmth for growing adds up to 2,902 growing degree days a year (base 50°F), more than at 97% of the 182 Wisconsin stations. 29% of them (855) have built up by the end of June, and July adds the most, 722. Precipitation totals 34.7 inches a year, most in June (4.4") and least in February (1.7"); May to September bring 52% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 31 | 17 | 1.8 | 100% | 28 | 0 |
| Feb | 34 | 20 | 1.7 | 100% | 25 | 1 |
| Mar | 44 | 29 | 2.2 | 100% | 21 | 17 |
| Apr | 55 | 38 | 3.9 | 96% | 6 | 60 |
| May | 67 | 48 | 3.5 | 12% | <1 | 249 |
| Jun | 77 | 58 | 4.4 | 0% | 0 | 528 |
| Jul | 82 | 65 | 3.4 | 0% | 0 | 722 |
| Aug | 80 | 64 | 3.7 | 0% | 0 | 690 |
| Sep | 74 | 56 | 3.2 | 0% | 0 | 451 |
| Oct | 61 | 45 | 2.8 | 60% | 2 | 159 |
| Nov | 48 | 33 | 2.2 | 100% | 15 | 25 |
| Dec | 36 | 23 | 1.9 | 100% | 25 | 1 |
Monthly normals 1991–2020 at Milwaukee Mitchell Airport, WI (670 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, West Allis, WI, 6 miles northwest of Milwaukee, has a last frost 7 days later (April 26), a first frost 7 days earlier (October 22), a season 15 days shorter.
When it snows in Milwaukee, Wisconsin
The first measurable snow (0.1 inch or more) in Milwaukee usually arrives around November 13, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Milwaukee Mitchell Airport, WI, 2.1 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 6 days after the last snow.
Planting calendar for 53207
| When | What to do |
|---|---|
| February 8 – February 22 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 22 – March 8 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 22 – April 5 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 19 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 6 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 15 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 29 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 53207 is 2 miles from Milwaukee Mitchell Airport, WI, which stands at 670 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 53221 (Milwaukee). The 2023 USDA Plant Hardiness Zone Map lists ZIP 53207 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Wisconsin →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.