USDA Hardiness Zone 6b
Frost Dates for 48230 — Grosse Pointe, Michigan
NOAA 1991–2020 normals from Grosse Pointe Farms, MI (613 ft), 2 miles northeast.
Updated
In Grosse Pointe, the last spring frost (32°F) is around April 29 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 22, as early as October 7 one year in ten, leaving a typical freeze-free season of 176 days (NOAA, Grosse Pointe Farms, MI).
- Last spring frost
- April 29
- First fall frost
- October 22
- Growing season
- 176 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 8
- Last snow
- March 15
- Winters with snow
- 100%
- Snow per year
- 27.9"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Grosse Pointe
Half of springs at Grosse Pointe Farms, MI see their last 32°F night by April 29; only one in ten is past it by April 15, and one in ten still has one after May 13. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 8 20%, and after May 13 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 80% of the 172 Michigan stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 22 in half of years, as early as October 7 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 10 days later, around November 1; in spring the one-in-ten date for 28°F is May 2, 11 days before the 32°F one. The freeze-free season lasts 176 days in a typical year, longer than at 90% of the 172 Michigan stations; it reaches 194 days one year in ten and falls short of 155 one year in ten. On average 124 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 8, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 5 and March 18.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 25 | Apr 30 | May 2 | May 5 | May 8 | May 11 | May 14 | May 18 | May 22 |
| 32°F | Apr 15 | Apr 18 | Apr 22 | Apr 25 | Apr 29 | Apr 30 | May 3 | May 8 | May 13 |
| 28°F | Apr 3 | Apr 7 | Apr 11 | Apr 13 | Apr 16 | Apr 19 | Apr 22 | Apr 27 | May 2 |
| 24°F | Mar 23 | Mar 29 | Apr 1 | Apr 3 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 18 |
| 20°F | Mar 12 | Mar 17 | Mar 21 | Mar 23 | Mar 27 | Mar 30 | Apr 1 | Apr 4 | Apr 9 |
| 16°F | Mar 2 | Mar 8 | Mar 11 | Mar 15 | Mar 18 | Mar 21 | Mar 24 | Mar 29 | Apr 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 26 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 24 |
| 32°F | Oct 7 | Oct 12 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 |
| 28°F | Oct 19 | Oct 24 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 14 |
| 24°F | Oct 30 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 29 |
| 20°F | Nov 6 | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 27 | Dec 1 | Dec 5 | Dec 13 |
| 16°F | Nov 15 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 19 | Dec 25 |
Freeze probabilities 1991–2020 at Grosse Pointe Farms, MI, 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 48230 →Compare Grosse Pointe with another place →
Weather by month in Grosse Pointe
July is the warmest month at Grosse Pointe Farms, MI, averaging 82°F by day and 62°F at night; January is the coldest at 32°F and 17°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 40% of years.
Warmth for growing adds up to 2,711 growing degree days a year (base 50°F), more than at 75% of the 172 Michigan stations. 31% of them (840) have built up by the end of June, and July adds the most, 688. Precipitation totals 36.0 inches a year, most in May (3.9") and least in January (2.1"); May to September bring 49% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 32 | 17 | 2.1 | 100% | 28 | 0 |
| Feb | 34 | 18 | 2.2 | 100% | 25 | 0 |
| Mar | 43 | 25 | 2.6 | 100% | 23 | 10 |
| Apr | 56 | 36 | 3.4 | 100% | 8 | 56 |
| May | 67 | 48 | 3.9 | 40% | <1 | 250 |
| Jun | 77 | 58 | 3.6 | 0% | 0 | 525 |
| Jul | 82 | 62 | 3.4 | 0% | 0 | 688 |
| Aug | 80 | 61 | 3.5 | 0% | 0 | 635 |
| Sep | 73 | 54 | 3.3 | 2% | 0 | 402 |
| Oct | 60 | 43 | 2.8 | 80% | 2 | 128 |
| Nov | 47 | 32 | 2.8 | 100% | 14 | 15 |
| Dec | 37 | 24 | 2.4 | 100% | 25 | 2 |
Monthly normals 1991–2020 at Grosse Pointe Farms, MI (613 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 City Airport, MI, 5 miles west of Grosse Pointe, has a last frost 8 days earlier (April 21), a first frost 9 days later (October 31), a season 14 days longer.
When it snows in Grosse Pointe, Michigan
The first measurable snow (0.1 inch or more) in Grosse Pointe usually arrives around December 8, and the last of the season around March 15. Those are the middle dates across the winters of 1991–2020 at Grosse Pointe Farms, MI, 2.3 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 45 days after the last snow.
Planting calendar for 48230
| When | What to do |
|---|---|
| February 18 – March 4 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 4 – March 18 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 1 – April 15 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 29 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 30 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 8 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 22 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 48230 is 2 miles from Grosse Pointe Farms, MI, which stands at 613 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 48066 (Roseville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48230 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.
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.