USDA Hardiness Zone 6a
Frost Dates for 49286 — Tecumseh, Michigan
NOAA 1991–2020 normals from Tecumseh, MI (780 ft), under a mile south.
Updated
In Tecumseh, the last spring frost (32°F) is around May 3 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 13, as early as September 30 one year in ten, leaving a typical freeze-free season of 160 days (NOAA, Tecumseh, MI).
- Last spring frost
- May 3
- First fall frost
- October 13
- Growing season
- 160 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
- December 3
- Last snow
- March 14
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
18 of 18 observed
NOAA normal
Frost risk by date in Tecumseh
Half of springs at Tecumseh, MI see their last 32°F night by May 3; only one in ten is past it by April 20, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 12 20%, and after May 18 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 13 in half of years, as early as September 30 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 12 days later, around October 25; in spring the one-in-ten date for 28°F is May 7, 11 days before the 32°F one. The freeze-free season lasts 160 days in a typical year, longer than at 51% of the 172 Michigan stations; it reaches 180 days one year in ten and falls short of 141 one year in ten. On average 151 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 14, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 29 and March 20.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | May 4 | May 8 | May 11 | May 14 | May 17 | May 20 | May 24 | May 29 |
| 32°F | Apr 20 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 6 | May 9 | May 12 | May 18 |
| 28°F | Apr 9 | Apr 14 | Apr 17 | Apr 20 | Apr 23 | Apr 26 | Apr 30 | May 3 | May 7 |
| 24°F | Mar 29 | Apr 3 | Apr 5 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 22 | Apr 28 |
| 20°F | Mar 15 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 8 | Apr 15 |
| 16°F | Mar 4 | Mar 10 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 28 | Mar 31 | Apr 3 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 23 | Sep 27 | Sep 30 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 |
| 32°F | Sep 30 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 25 |
| 28°F | Oct 10 | Oct 16 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 6 |
| 24°F | Oct 24 | Oct 30 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 12 | Nov 16 | Nov 21 |
| 20°F | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 2 |
| 16°F | Nov 12 | Nov 18 | Nov 22 | Nov 26 | Nov 29 | Dec 1 | Dec 5 | Dec 11 | Dec 18 |
Freeze probabilities 1991–2020 at Tecumseh, 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 49286 →Compare Tecumseh with another place →
Weather by month in Tecumseh
July is the warmest month at Tecumseh, MI, averaging 86°F by day and 59°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 59% of years.
Warmth for growing adds up to 2,734 growing degree days a year (base 50°F), more than at 78% of the 172 Michigan stations. 33% of them (893) have built up by the end of June, and July adds the most, 690.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 33 | 15 | 100% | 29 | 0 |
| Feb | 36 | 16 | 100% | 27 | 0 |
| Mar | 46 | 24 | 100% | 25 | 12 |
| Apr | 60 | 34 | 100% | 12 | 67 |
| May | 71 | 45 | 59% | 2 | 271 |
| Jun | 81 | 55 | 0% | 0 | 543 |
| Jul | 86 | 59 | 0% | 0 | 690 |
| Aug | 83 | 57 | 0% | 0 | 618 |
| Sep | 76 | 50 | 11% | <1 | 394 |
| Oct | 63 | 39 | 96% | 8 | 125 |
| Nov | 49 | 29 | 100% | 20 | 13 |
| Dec | 38 | 21 | 100% | 28 | 2 |
Monthly normals 1991–2020 at Tecumseh, MI (780 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 2 NNE, MI, 8 miles southwest of Tecumseh, has a last frost 2 days earlier (May 1), a first frost 2 days later (October 15), a season 4 days longer.
When it snows in Tecumseh, Michigan
The first measurable snow (0.1 inch or more) in Tecumseh usually arrives around December 3, and the last of the season around March 14. Those are the middle dates across the winters of 1991–2020 at Tecumseh, MI, 0.7 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 50 days after the last snow.
Planting calendar for 49286
| When | What to do |
|---|---|
| February 22 – March 8 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 8 – March 22 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 5 – April 19 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 21 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 29 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 13 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 49286 is under a mile from Tecumseh, MI, which stands at 780 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 49286 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.