USDA Hardiness Zone 4b
Frost Dates for 54618 — Camp Douglas, Wisconsin
NOAA 1991–2020 normals from Necedah 5 WNW, WI (933 ft), 9 miles northeast.
Updated
In Camp Douglas, the last spring frost (32°F) is around May 1 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 3, as early as September 20 one year in ten, leaving a typical freeze-free season of 157 days (NOAA, Necedah 5 WNW, WI).
- Last spring frost
- May 1
- First fall frost
- October 3
- Growing season
- 157 days
- Hardiness zone
- 4b
50% probability
50% probability
freeze-free, 50%
-25 to -20°F (-31.7 to -28.9°C) coldest night
- First snow
- November 28
- Last snow
- April 5
- Winters with snow
- 95%
- Snow per year
- 34.1"
median, 1991–2020
median, 1991–2020
20 of 21 observed
NOAA normal
Frost risk by date in Camp Douglas
Half of springs at Necedah 5 WNW, WI see their last 32°F night by May 1; only one in ten is past it by April 17, and one in ten still has one after May 14. Planting tender crops after May 5 leaves a 30% risk of a frost on them, after May 9 20%, and after May 14 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 3 in half of years, as early as September 20 one year in ten, and holds off past October 18 one year in ten. A hard freeze of 28°F follows 12 days later, around October 15; in spring the one-in-ten date for 28°F is May 3, 11 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, longer than at 53% of the 182 Wisconsin stations; it reaches 176 days one year in ten and falls short of 137 one year in ten. On average 154 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 9 days longer, to about May 10, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 17 and March 25.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 28 | May 1 | May 5 | May 7 | May 10 | May 13 | May 16 | May 20 | May 26 |
| 32°F | Apr 17 | Apr 22 | Apr 25 | Apr 29 | May 1 | May 3 | May 5 | May 9 | May 14 |
| 28°F | Apr 5 | Apr 9 | Apr 13 | Apr 16 | Apr 20 | Apr 22 | Apr 26 | Apr 29 | May 3 |
| 24°F | Mar 28 | Apr 1 | Apr 3 | Apr 6 | Apr 8 | Apr 11 | Apr 14 | Apr 17 | Apr 23 |
| 20°F | Mar 18 | Mar 23 | Mar 27 | Mar 31 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 14 |
| 16°F | Mar 10 | Mar 15 | Mar 19 | Mar 22 | Mar 25 | Mar 27 | Mar 31 | Apr 2 | Apr 5 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 12 | Sep 17 | Sep 20 | Sep 23 | Sep 25 | Sep 27 | Sep 30 | Oct 3 | Oct 6 |
| 32°F | Sep 20 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 18 |
| 28°F | Sep 29 | Oct 4 | Oct 8 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 25 | Oct 31 |
| 24°F | Oct 12 | Oct 18 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 13 |
| 20°F | Oct 27 | Oct 31 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 14 | Nov 18 | Nov 23 |
| 16°F | Nov 3 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 19 | Nov 23 | Nov 26 | Dec 1 |
Freeze probabilities 1991–2020 at Necedah 5 WNW, 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 54618 →Compare Camp Douglas with another place →
Weather by month in Camp Douglas
July is the warmest month at Necedah 5 WNW, WI, averaging 81°F by day and 60°F at night; January is the coldest at 25°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 50% of years.
Warmth for growing adds up to 2,454 growing degree days a year (base 50°F), more than at 53% of the 182 Wisconsin stations. 35% of them (847) have built up by the end of June, and July adds the most, 634. Precipitation totals 34.6 inches a year, most in August (4.5") and least in January (1.3"); May to September bring 58% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 25 | 8 | 1.3 | 100% | 30 | 0 |
| Feb | 30 | 11 | 1.3 | 100% | 27 | 0 |
| Mar | 42 | 23 | 2.1 | 100% | 24 | 16 |
| Apr | 56 | 35 | 3.4 | 100% | 11 | 63 |
| May | 69 | 47 | 4.0 | 50% | 1 | 267 |
| Jun | 77 | 57 | 4.4 | 0% | 0 | 501 |
| Jul | 81 | 60 | 3.9 | 0% | 0 | 634 |
| Aug | 79 | 58 | 4.5 | 0% | 0 | 561 |
| Sep | 71 | 49 | 3.4 | 40% | 1 | 317 |
| Oct | 58 | 38 | 2.7 | 99% | 9 | 87 |
| Nov | 43 | 26 | 1.9 | 100% | 22 | 7 |
| Dec | 30 | 15 | 1.7 | 100% | 29 | 0 |
Monthly normals 1991–2020 at Necedah 5 WNW, WI (933 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, Necedah, WI, 12 miles northeast of Camp Douglas, has a last frost 16 days later (May 17), a first frost 8 days earlier (September 25), a season 26 days shorter.
When it snows in Camp Douglas, Wisconsin
The first measurable snow (0.1 inch or more) in Camp Douglas usually arrives around November 28, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Necedah, WI, 11.6 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 26 days after the last snow.
Planting calendar for 54618
| When | What to do |
|---|---|
| February 20 – March 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 6 – March 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 3 – April 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 1 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 3 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 54618 is 9 miles from Necedah 5 WNW, WI, which stands at 933 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 54618 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°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.