USDA Hardiness Zone 5a
Frost Dates for 53086 — Slinger, Wisconsin
NOAA 1991–2020 normals from Slinger Wwtp, WI (1,029 ft), under a mile west.
Updated
In Slinger, the last spring frost (32°F) is around May 5 in half of years and has passed by May 20 in nine years out of ten. The first fall frost comes around October 5, as early as September 22 one year in ten, leaving a typical freeze-free season of 152 days (NOAA, Slinger Wwtp, WI).
- Last spring frost
- May 5
- First fall frost
- October 5
- Growing season
- 152 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 27
- Last snow
- March 28
- Winters with snow
- 100%
- Snow per year
- 36.3"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Slinger
Half of springs at Slinger Wwtp, WI see their last 32°F night by May 5; only one in ten is past it by April 21, and one in ten still has one after May 20. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 15 20%, and after May 20 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 30% of the 182 Wisconsin stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 5 in half of years, as early as September 22 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 12 days later, around October 17; in spring the one-in-ten date for 28°F is May 9, 11 days before the 32°F one. The freeze-free season lasts 152 days in a typical year, shorter than at 59% of the 182 Wisconsin stations; it reaches 170 days one year in ten and falls short of 133 one year in ten. On average 168 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 17, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 19 and March 27.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 2 | May 7 | May 11 | May 14 | May 17 | May 20 | May 23 | May 27 | May 31 |
| 32°F | Apr 21 | Apr 26 | Apr 30 | May 2 | May 5 | May 8 | May 11 | May 15 | May 20 |
| 28°F | Apr 11 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 4 | May 9 |
| 24°F | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 13 | Apr 16 | Apr 20 | Apr 24 | Apr 29 |
| 20°F | Mar 21 | Mar 26 | Mar 31 | Apr 2 | Apr 3 | Apr 5 | Apr 7 | Apr 11 | Apr 16 |
| 16°F | Mar 11 | Mar 16 | Mar 19 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 3 | Apr 7 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 12 | Sep 18 | Sep 22 | Sep 24 | Sep 28 | Sep 30 | Oct 3 | Oct 5 | Oct 8 |
| 32°F | Sep 22 | Sep 27 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 20 |
| 28°F | Oct 1 | Oct 6 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Oct 31 |
| 24°F | Oct 14 | Oct 20 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 13 |
| 20°F | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 15 | Nov 20 | Nov 25 |
| 16°F | Nov 4 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 22 | Nov 24 | Nov 29 | Dec 4 |
Freeze probabilities 1991–2020 at Slinger Wwtp, 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 53086 →Compare Slinger with another place →
Weather by month in Slinger
July is the warmest month at Slinger Wwtp, WI, averaging 80°F by day and 59°F at night; January is the coldest at 26°F and 8°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 64% of years.
Warmth for growing adds up to 2,240 growing degree days a year (base 50°F), fewer than at 72% of the 182 Wisconsin stations. 31% of them (701) have built up by the end of June, and July adds the most, 595.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 26 | 8 | 100% | 31 | 0 |
| Feb | 29 | 11 | 100% | 27 | 0 |
| Mar | 40 | 21 | 100% | 27 | 14 |
| Apr | 54 | 33 | 100% | 18 | 39 |
| May | 65 | 45 | 64% | 2 | 200 |
| Jun | 76 | 54 | 0% | 0 | 448 |
| Jul | 80 | 59 | 0% | 0 | 595 |
| Aug | 78 | 56 | 0% | 0 | 533 |
| Sep | 71 | 49 | 29% | 1 | 314 |
| Oct | 58 | 37 | 99% | 12 | 86 |
| Nov | 43 | 26 | 100% | 23 | 11 |
| Dec | 31 | 16 | 100% | 29 | 0 |
Monthly normals 1991–2020 at Slinger Wwtp, WI (1,029 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, Jackson, WI, 6 miles east of Slinger, has a last frost 5 days earlier (April 30), a first frost 10 days later (October 15), a season 15 days longer.
When it snows in Slinger, Wisconsin
The first measurable snow (0.1 inch or more) in Slinger usually arrives around November 27, and the last of the season around March 28. Those are the middle dates across the winters of 1991–2020 at Hartford Wwtp, WI, 6.7 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 38 days after the last snow.
Planting calendar for 53086
| When | What to do |
|---|---|
| February 24 – March 10 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 10 – March 24 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 7 – April 21 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 5 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 53086 is under a mile from Slinger Wwtp, WI, which stands at 1,029 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 53086 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°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.