USDA Hardiness Zone 4a
Frost Dates for 55760 — Mcgregor, Minnesota
NOAA 1991–2020 normals from Sandy Lake Dam Libby, MN (1,234 ft), 8 miles north.
Updated
In Mcgregor, the last spring frost (32°F) is around May 7 in half of years and has passed by May 21 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 148 days (NOAA, Sandy Lake Dam Libby, MN).
- Last spring frost
- May 7
- First fall frost
- October 3
- Growing season
- 148 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
- October 30
- Last snow
- April 21
- Winters with snow
- 100%
- Snow per year
- 59.2"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Mcgregor
Half of springs at Sandy Lake Dam Libby, MN see their last 32°F night by May 7; only one in ten is past it by April 26, and one in ten still has one after May 21. Planting tender crops after May 13 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 37% of the 142 Minnesota 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 17 one year in ten. A hard freeze of 28°F follows 10 days later, around October 13; in spring the one-in-ten date for 28°F is May 10, 11 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 59% of the 142 Minnesota stations; it reaches 166 days one year in ten and falls short of 130 one year in ten. On average 182 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 19, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 10 and April 3.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 5 | May 9 | May 13 | May 16 | May 19 | May 21 | May 24 | May 28 | Jun 1 |
| 32°F | Apr 26 | Apr 30 | May 2 | May 5 | May 7 | May 9 | May 13 | May 16 | May 21 |
| 28°F | Apr 16 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 3 | May 6 | May 10 |
| 24°F | Apr 6 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 24 | Apr 28 | May 1 |
| 20°F | Mar 31 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 12 | Apr 16 | Apr 19 | Apr 23 |
| 16°F | Mar 21 | Mar 27 | Mar 31 | Apr 2 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 11 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 26 | Sep 29 | Oct 2 | Oct 6 |
| 32°F | Sep 20 | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 17 |
| 28°F | Sep 30 | Oct 4 | Oct 7 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 24°F | Oct 10 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 31 | Nov 3 | Nov 8 |
| 20°F | Oct 20 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 18 |
| 16°F | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 24 |
Freeze probabilities 1991–2020 at Sandy Lake Dam Libby, 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 55760 →Compare Mcgregor with another place →
Compared with the next station
The nearest other station, Aitkin 2E, MN, 21 miles southwest of Mcgregor, has a last frost 9 days later (May 16), a first frost 5 days earlier (September 28), a season 15 days shorter.
When it snows in Mcgregor, Minnesota
The first measurable snow (0.1 inch or more) in Mcgregor usually arrives around October 30, and the last of the season around April 21. Those are the middle dates across the winters of 1991–2020 at Wright 3 E, MN, 15.6 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 16 days after the last snow.
Planting calendar for 55760
| When | What to do |
|---|---|
| February 26 – March 12 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 12 – March 26 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 9 – April 23 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 7 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 55760 is 8 miles from Sandy Lake Dam Libby, MN, which stands at 1,234 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 55760 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.