USDA Hardiness Zone 4a
Frost Dates for 56501 — Detroit Lakes, Minnesota
NOAA 1991–2020 normals from Detroit Lakes 1 NNE, MN (1,355 ft), 2 miles north.
Updated
In Detroit Lakes, the last spring frost (32°F) is around May 15 in half of years and has passed by May 30 in nine years out of ten. The first fall frost comes around September 24, as early as September 9 one year in ten, leaving a typical freeze-free season of 130 days (NOAA, Detroit Lakes 1 NNE, MN).
- Last spring frost
- May 15
- First fall frost
- September 24
- Growing season
- 130 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 28
- Last snow
- April 16
- Winters with snow
- 100%
- Snow per year
- 47.6"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Detroit Lakes
Half of springs at Detroit Lakes 1 NNE, MN see their last 32°F night by May 15; only one in ten is past it by May 2, and one in ten still has one after May 30. Planting tender crops after May 22 leaves a 30% risk of a frost on them, after May 26 20%, and after May 30 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 64% of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 24 in half of years, as early as September 9 one year in ten, and holds off past October 6 one year in ten. A hard freeze of 28°F follows 9 days later, around October 3; in spring the one-in-ten date for 28°F is May 19, 11 days before the 32°F one. The freeze-free season lasts 130 days in a typical year, shorter than at 92% of the 142 Minnesota stations; it reaches 150 days one year in ten and falls short of 111 one year in ten. On average 177 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 11 days longer, to about May 26, and return around September 13. Severe cold of 16°F or below comes every winter, usually between November 3 and April 10.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 12 | May 17 | May 20 | May 24 | May 26 | May 29 | May 31 | Jun 3 | Jun 7 |
| 32°F | May 2 | May 6 | May 9 | May 12 | May 15 | May 18 | May 22 | May 26 | May 30 |
| 28°F | Apr 24 | Apr 28 | May 1 | May 3 | May 5 | May 8 | May 10 | May 13 | May 19 |
| 24°F | Apr 13 | Apr 17 | Apr 21 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 4 | May 9 |
| 20°F | Apr 4 | Apr 9 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 23 | Apr 27 | May 1 |
| 16°F | Mar 27 | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 20 | Apr 24 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 28 | Sep 3 | Sep 6 | Sep 10 | Sep 13 | Sep 16 | Sep 19 | Sep 22 | Sep 27 |
| 32°F | Sep 9 | Sep 14 | Sep 18 | Sep 21 | Sep 24 | Sep 26 | Sep 30 | Oct 2 | Oct 6 |
| 28°F | Sep 18 | Sep 24 | Sep 27 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 18 |
| 24°F | Sep 29 | Oct 3 | Oct 6 | Oct 10 | Oct 14 | Oct 17 | Oct 21 | Oct 25 | Oct 29 |
| 20°F | Oct 7 | Oct 13 | Oct 18 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 19 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 8 | Nov 12 | Nov 18 |
Freeze probabilities 1991–2020 at Detroit Lakes 1 NNE, 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 56501 →Compare Detroit Lakes with another place →
Weather by month in Detroit Lakes
July is the warmest month at Detroit Lakes 1 NNE, MN, averaging 79°F by day and 58°F at night; January is the coldest at 17°F and -4°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 2,049 growing degree days a year (base 50°F), fewer than at 77% of the 142 Minnesota stations. 32% of them (661) have built up by the end of June, and July adds the most, 569. Precipitation totals 29.6 inches a year, most in June (4.9") and least in February (0.7"); May to September bring 67% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 17 | -4 | 0.8 | 100% | 31 | 0 |
| Feb | 23 | 0 | 0.7 | 100% | 28 | 0 |
| Mar | 36 | 15 | 1.0 | 100% | 27 | 3 |
| Apr | 52 | 29 | 2.0 | 100% | 17 | 33 |
| May | 66 | 42 | 3.7 | 93% | 4 | 195 |
| Jun | 76 | 53 | 4.9 | 7% | <1 | 431 |
| Jul | 79 | 58 | 4.4 | 0% | 0 | 569 |
| Aug | 78 | 55 | 3.3 | 2% | 0 | 512 |
| Sep | 70 | 46 | 3.6 | 73% | 2 | 263 |
| Oct | 53 | 34 | 2.8 | 100% | 12 | 44 |
| Nov | 37 | 19 | 1.4 | 100% | 26 | 1 |
| Dec | 22 | 6 | 1.0 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Detroit Lakes 1 NNE, MN (1,355 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, Detroit Lakes 12E, MN, 12 miles east of Detroit Lakes and 187 feet higher, has a last frost 11 days earlier (May 4), a first frost 9 days later (October 3), a season 20 days longer.
When it snows in Detroit Lakes, Minnesota
The first measurable snow (0.1 inch or more) in Detroit Lakes usually arrives around October 28, and the last of the season around April 16. Those are the middle dates across the winters of 1991–2020 at Detroit Lakes 1 NNE, MN, 2 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 29 days after the last snow.
Planting calendar for 56501
| When | What to do |
|---|---|
| March 6 – March 20 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 20 – April 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 17 – May 1 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 15 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 2 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 10 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 24 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 56501 is 2 miles from Detroit Lakes 1 NNE, MN, which stands at 1,355 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 56501 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.