USDA Hardiness Zone 4a
Frost Dates for 55007 — Brook Park, Minnesota
NOAA 1991–2020 normals from Hinckley, MN (1,035 ft), 6 miles northeast.
Updated
In Brook Park, the last spring frost (32°F) is around May 16 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, Hinckley, MN).
- Last spring frost
- May 16
- 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
- November 7
- Last snow
- April 9
- Winters with snow
- 100%
- Snow per year
- 44.8"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Brook Park
Half of springs at Hinckley, MN see their last 32°F night by May 16; only one in ten is past it by May 3, 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 25 20%, and after May 30 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 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 8 days later, around October 2; in spring the one-in-ten date for 28°F is May 20, 10 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 183 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 28, and return around September 15. Severe cold of 16°F or below comes every winter, usually between November 7 and April 4.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 15 | May 20 | May 23 | May 25 | May 28 | May 30 | Jun 1 | Jun 4 | Jun 9 |
| 32°F | May 3 | May 7 | May 11 | May 14 | May 16 | May 19 | May 22 | May 25 | May 30 |
| 28°F | Apr 21 | Apr 26 | Apr 29 | May 1 | May 4 | May 8 | May 11 | May 15 | May 20 |
| 24°F | Apr 9 | Apr 14 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 3 | May 10 |
| 20°F | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 27 |
| 16°F | Mar 20 | Mar 27 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 18 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 31 | Sep 5 | Sep 8 | Sep 12 | Sep 15 | Sep 18 | Sep 21 | Sep 24 | Sep 29 |
| 32°F | Sep 9 | Sep 14 | Sep 17 | Sep 21 | Sep 24 | Sep 27 | Sep 30 | Oct 3 | Oct 6 |
| 28°F | Sep 16 | Sep 22 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 12 | Oct 17 |
| 24°F | Sep 25 | Oct 2 | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 24 | Oct 30 |
| 20°F | Oct 9 | Oct 16 | Oct 21 | Oct 24 | Oct 28 | Oct 31 | Nov 2 | Nov 6 | Nov 10 |
| 16°F | Oct 23 | Oct 30 | Nov 1 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 17 | Nov 22 |
Freeze probabilities 1991–2020 at Hinckley, 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 55007 →Compare Brook Park with another place →
Weather by month in Brook Park
July is the warmest month at Hinckley, MN, averaging 79°F by day and 55°F at night; January is the coldest at 19°F and -1°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 1,819 growing degree days a year (base 50°F), fewer than at 89% of the 142 Minnesota stations. 30% of them (555) have built up by the end of June, and July adds the most, 531. Precipitation totals 33.1 inches a year, most in June (4.6") and least in February (0.9"); May to September bring 62% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 19 | -1 | 1.0 | 100% | 31 | 0 |
| Feb | 25 | 3 | 0.9 | 100% | 27 | 0 |
| Mar | 38 | 16 | 1.6 | 100% | 28 | 2 |
| Apr | 52 | 28 | 2.8 | 100% | 18 | 23 |
| May | 65 | 40 | 3.8 | 93% | 4 | 153 |
| Jun | 75 | 50 | 4.6 | 6% | 0 | 377 |
| Jul | 79 | 55 | 4.1 | 0% | 0 | 531 |
| Aug | 77 | 52 | 4.3 | 1% | 0 | 460 |
| Sep | 69 | 44 | 3.6 | 70% | 3 | 231 |
| Oct | 55 | 32 | 3.5 | 100% | 14 | 40 |
| Nov | 39 | 21 | 1.6 | 100% | 27 | 1 |
| Dec | 26 | 9 | 1.3 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Hinckley, MN (1,035 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, Mora, MN, 11 miles southwest of Brook Park, has a last frost 7 days earlier (May 9), a first frost 6 days later (September 30), a season 12 days longer.
When it snows in Brook Park, Minnesota
The first measurable snow (0.1 inch or more) in Brook Park usually arrives around November 7, and the last of the season around April 9. Those are the middle dates across the winters of 1991–2020 at Hinckley, MN, 5.9 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 37 days after the last snow.
Planting calendar for 55007
| When | What to do |
|---|---|
| March 7 – March 21 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 21 – April 4 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 18 – May 2 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 16 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 55007 is 6 miles from Hinckley, MN, which stands at 1,035 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 55063 (Pine City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55007 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.