USDA Hardiness Zone 4a
Frost Dates for 56330 — Foreston, Minnesota
NOAA 1991–2020 normals from Milaca, MN (1,064 ft), 4 miles northeast.
Updated
In Foreston, the last spring frost (32°F) is around May 8 in half of years and has passed by May 26 in nine years out of ten. The first fall frost comes around October 1, as early as September 17 one year in ten, leaving a typical freeze-free season of 143 days (NOAA, Milaca, MN).
- Last spring frost
- May 8
- First fall frost
- October 1
- Growing season
- 143 days
- Hardiness zone
- 4a
50% probability
50% probability
freeze-free, 50%
-30 to -25°F (-34.4 to -31.7°C) coldest night
- First snow
- November 11
- Last snow
- April 12
- Winters with snow
- 100%
- Snow per year
- 48.9"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Foreston
Half of springs at Milaca, MN see their last 32°F night by May 8; only one in ten is past it by April 25, and one in ten still has one after May 26. Planting tender crops after May 16 leaves a 30% risk of a frost on them, after May 20 20%, and after May 26 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 92% of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 1 in half of years, as early as September 17 one year in ten, and holds off past October 14 one year in ten. A hard freeze of 28°F follows 10 days later, around October 11; in spring the one-in-ten date for 28°F is May 14, 12 days before the 32°F one. The freeze-free season lasts 143 days in a typical year, shorter than at 71% of the 142 Minnesota stations; it reaches 162 days one year in ten and falls short of 121 one year in ten. On average 178 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 20, and return around September 22. Severe cold of 16°F or below comes every winter, usually between November 9 and April 2.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 5 | May 10 | May 14 | May 18 | May 20 | May 23 | May 27 | May 31 | Jun 3 |
| 32°F | Apr 25 | Apr 30 | May 2 | May 5 | May 8 | May 12 | May 16 | May 20 | May 26 |
| 28°F | Apr 14 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 8 | May 14 |
| 24°F | Apr 4 | Apr 8 | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | May 1 |
| 20°F | Mar 27 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 13 | Apr 18 | Apr 22 |
| 16°F | Mar 18 | Mar 23 | Mar 28 | Mar 31 | Apr 2 | Apr 3 | Apr 5 | Apr 8 | Apr 14 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 9 | Sep 14 | Sep 17 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Oct 1 | Oct 5 |
| 32°F | Sep 17 | Sep 21 | Sep 24 | Sep 27 | Oct 1 | Oct 3 | Oct 5 | Oct 9 | Oct 14 |
| 28°F | Sep 25 | Oct 1 | Oct 4 | Oct 7 | Oct 11 | Oct 13 | Oct 17 | Oct 21 | Oct 25 |
| 24°F | Oct 5 | Oct 10 | Oct 15 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 20°F | Oct 18 | Oct 23 | Oct 27 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 |
| 16°F | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 11 | Nov 14 | Nov 18 | Nov 22 |
Freeze probabilities 1991–2020 at Milaca, MN, 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 56330 →Compare Foreston with another place →
Weather by month in Foreston
July is the warmest month at Milaca, MN, averaging 80°F by day and 59°F at night; January is the coldest at 20°F and 1°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 75% of years.
Warmth for growing adds up to 2,122 growing degree days a year (base 50°F), fewer than at 73% of the 142 Minnesota stations. 32% of them (670) have built up by the end of June, and July adds the most, 600. Precipitation totals 30.8 inches a year, most in July (4.4") and least in January (0.8"); May to September bring 64% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 20 | 1 | 0.8 | 100% | 31 | 0 |
| Feb | 26 | 4 | 0.9 | 100% | 28 | 0 |
| Mar | 38 | 17 | 1.4 | 100% | 28 | 3 |
| Apr | 53 | 30 | 2.7 | 100% | 18 | 31 |
| May | 66 | 43 | 3.8 | 75% | 2 | 193 |
| Jun | 76 | 54 | 4.3 | 3% | 0 | 442 |
| Jul | 80 | 59 | 4.4 | 0% | 0 | 600 |
| Aug | 78 | 56 | 4.0 | 0% | 0 | 524 |
| Sep | 70 | 46 | 3.2 | 50% | 2 | 272 |
| Oct | 56 | 34 | 2.8 | 100% | 13 | 54 |
| Nov | 39 | 21 | 1.4 | 100% | 26 | 3 |
| Dec | 26 | 9 | 1.1 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Milaca, MN (1,064 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, Santiago 3 E, MN, 13 miles south of Foreston, has a last frost 1 day earlier (May 7), a first frost 3 days earlier (September 28), a season 1 day longer.
When it snows in Foreston, Minnesota
The first measurable snow (0.1 inch or more) in Foreston usually arrives around November 11, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Milaca, MN, 3.6 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 26 days after the last snow.
Planting calendar for 56330
| When | What to do |
|---|---|
| February 27 – March 13 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 13 – March 27 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 10 – April 24 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 9 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 17 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 1 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 56330 is 4 miles from Milaca, MN, which stands at 1,064 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 56353 (Milaca). The 2023 USDA Plant Hardiness Zone Map lists ZIP 56330 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Minnesota →
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.