USDA Hardiness Zone 6a
Frost Dates for 49247 — Hudson, Michigan
NOAA 1991–2020 normals from Morenci, MI (770 ft), 12 miles southeast.
Updated
In Hudson, the last spring frost (32°F) is around May 4 in half of years and has passed by May 19 in nine years out of ten. The first fall frost comes around October 7, as early as September 24 one year in ten, leaving a typical freeze-free season of 156 days (NOAA, Morenci, MI).
- Last spring frost
- May 4
- First fall frost
- October 7
- Growing season
- 156 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- November 27
- Last snow
- March 27
- Winters with snow
- 100%
- Snow per year
- 33.3"
median, 1991–2020
median, 1991–2020
21 of 21 observed
NOAA normal
Frost risk by date in Hudson
Half of springs at Morenci, MI see their last 32°F night by May 4; only one in ten is past it by April 22, and one in ten still has one after May 19. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 14 20%, and after May 19 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 55% of the 172 Michigan stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 7 in half of years, as early as September 24 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 13 days later, around October 20; in spring the one-in-ten date for 28°F is May 9, 10 days before the 32°F one. The freeze-free season lasts 156 days in a typical year, shorter than at 55% of the 172 Michigan stations; it reaches 174 days one year in ten and falls short of 134 one year in ten. On average 148 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 10 days longer, to about May 14, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 25 and March 23.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 1 | May 5 | May 8 | May 11 | May 14 | May 17 | May 21 | May 25 | May 30 |
| 32°F | Apr 22 | Apr 26 | Apr 30 | May 2 | May 4 | May 7 | May 9 | May 14 | May 19 |
| 28°F | Apr 13 | Apr 17 | Apr 20 | Apr 22 | Apr 25 | Apr 29 | May 1 | May 4 | May 9 |
| 24°F | Apr 1 | Apr 5 | Apr 9 | Apr 12 | Apr 15 | Apr 17 | Apr 20 | Apr 24 | May 1 |
| 20°F | Mar 17 | Mar 23 | Mar 28 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 12 | Apr 16 |
| 16°F | Mar 7 | Mar 11 | Mar 15 | Mar 19 | Mar 23 | Mar 27 | Mar 30 | Apr 2 | Apr 7 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 19 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 3 | Oct 6 | Oct 10 |
| 32°F | Sep 24 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 |
| 28°F | Oct 4 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 24°F | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 15 |
| 20°F | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 29 |
| 16°F | Nov 8 | Nov 13 | Nov 18 | Nov 21 | Nov 25 | Nov 28 | Dec 1 | Dec 5 | Dec 11 |
Freeze probabilities 1991–2020 at Morenci, 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 49247 →Compare Hudson with another place →
Weather by month in Hudson
July is the warmest month at Morenci, MI, averaging 86°F by day and 58°F at night; January is the coldest at 33°F and 15°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 65% of years.
Warmth for growing adds up to 2,727 growing degree days a year (base 50°F), more than at 77% of the 172 Michigan stations. 34% of them (936) have built up by the end of June, and July adds the most, 674. Precipitation totals 38.1 inches a year, most in May (4.1") and least in January (2.3"); May to September bring 49% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 15 | 2.3 | 100% | 29 | 1 |
| Feb | 36 | 16 | 2.3 | 100% | 27 | 1 |
| Mar | 47 | 24 | 2.8 | 100% | 24 | 17 |
| Apr | 60 | 34 | 3.6 | 100% | 11 | 70 |
| May | 72 | 46 | 4.1 | 65% | 1 | 293 |
| Jun | 82 | 56 | 3.8 | 0% | 0 | 555 |
| Jul | 86 | 58 | 3.8 | 0% | 0 | 674 |
| Aug | 83 | 56 | 3.8 | 0% | 0 | 612 |
| Sep | 76 | 49 | 3.1 | 24% | <1 | 377 |
| Oct | 63 | 38 | 3.0 | 98% | 7 | 113 |
| Nov | 49 | 29 | 3.0 | 100% | 20 | 14 |
| Dec | 37 | 20 | 2.5 | 100% | 27 | 2 |
Monthly normals 1991–2020 at Morenci, MI (770 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, Adrian Lenawee Co Airport, MI, 14 miles east of Hudson, has a last frost 7 days earlier (April 27), a first frost 13 days later (October 20), a season 17 days longer.
When it snows in Hudson, Michigan
The first measurable snow (0.1 inch or more) in Hudson usually arrives around November 27, and the last of the season around March 27. Those are the middle dates across the winters of 1991–2020 at Hudson 3 E, MI, 2.9 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 38 days after the last snow.
Planting calendar for 49247
| When | What to do |
|---|---|
| February 23 – March 9 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 9 – March 23 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 6 – April 20 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 4 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 15 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 7 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 49247 is 12 miles from Morenci, MI, which stands at 770 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 49247 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°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.