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USDA Hardiness Zone 6a

Frost Dates for 49047 — Dowagiac, Michigan

NOAA 1991–2020 normals from Dowagiac 1 W, MI (740 ft), 1 miles southwest.

Updated

In Dowagiac, the last spring frost (32°F) is around May 4 in half of years and has passed by May 22 in nine years out of ten. The first fall frost comes around October 11, as early as September 27 one year in ten, leaving a typical freeze-free season of 158 days (NOAA, Dowagiac 1 W, MI).

Last spring frost
May 4

50% probability

First fall frost
October 11

50% probability

Growing season
158 days

freeze-free, 50%

Hardiness zone
6a

-10 to -5°F (-23.3 to -20.6°C) coldest night

First snow
November 23

median, 1991–2020

Last snow
March 24

median, 1991–2020

Winters with snow
100%

29 of 29 observed

Snow per year
—

NOAA normal

Frost risk by date in Dowagiac

Half of springs at Dowagiac 1 W, MI see their last 32°F night by May 4; only one in ten is past it by April 21, and one in ten still has one after May 22. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 16 20%, and after May 22 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 81% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 11 in half of years, as early as September 27 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 15 days later, around October 26; in spring the one-in-ten date for 28°F is May 10, 12 days before the 32°F one. The freeze-free season lasts 158 days in a typical year, shorter than at 50% of the 172 Michigan stations; it reaches 180 days one year in ten and falls short of 135 one year in ten. On average 145 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 15, and return around September 30. Severe cold of 16°F or below comes every winter, usually between December 2 and March 22.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FApr 30May 4May 8May 12May 15May 18May 22May 26May 31
32°FApr 21Apr 25Apr 29May 2May 4May 8May 11May 16May 22
28°FApr 10Apr 14Apr 18Apr 21Apr 24Apr 28Apr 30May 4May 10
24°FMar 30Apr 3Apr 5Apr 8Apr 11Apr 14Apr 18Apr 22Apr 30
20°FMar 15Mar 21Mar 25Mar 29Mar 31Apr 2Apr 5Apr 8Apr 14
16°FMar 4Mar 11Mar 16Mar 19Mar 22Mar 25Mar 29Mar 31Apr 4
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FSep 15Sep 21Sep 24Sep 28Sep 30Oct 2Oct 5Oct 9Oct 13
32°FSep 27Oct 1Oct 5Oct 8Oct 11Oct 14Oct 17Oct 22Oct 27
28°FOct 8Oct 15Oct 19Oct 23Oct 26Oct 28Nov 1Nov 3Nov 7
24°FOct 23Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 17Nov 22
20°FNov 4Nov 8Nov 12Nov 16Nov 19Nov 23Nov 27Dec 2Dec 7
16°FNov 13Nov 20Nov 25Nov 30Dec 2Dec 6Dec 10Dec 16Dec 22

Freeze probabilities 1991–2020 at Dowagiac 1 W, 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 49047 →Compare Dowagiac with another place →

Weather by month in Dowagiac

July is the warmest month at Dowagiac 1 W, MI, averaging 82°F by day and 60°F at night; January is the coldest at 31°F and 16°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 62% of years.

Warmth for growing adds up to 2,634 growing degree days a year (base 50°F), more than at 65% of the 172 Michigan stations. 34% of them (895) have built up by the end of June, and July adds the most, 643. Precipitation totals 41.7 inches a year, most in June (4.3") and least in February (2.4"); May to September bring 48% of it.

Monthly normals 1991–2020 at Dowagiac 1 W, MI
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan31163.1100%290
Feb34182.4100%261
Mar44252.4100%2418
Apr57363.7100%1277
May69474.262%2276
Jun78574.31%<1524
Jul82604.10%0643
Aug80584.10%0587
Sep74513.417%1368
Oct61404.392%7119
Nov47312.9100%1819
Dec36232.8100%272

Monthly normals 1991–2020 at Dowagiac 1 W, MI (740 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, Eau Claire 4 NE, MI, 6 miles west of Dowagiac, has a last frost 12 days earlier (April 22), a first frost 19 days later (October 30), a season 31 days longer.

Frost dates for 49103 (Berrien Springs) →

When it snows in Dowagiac, Michigan

The first measurable snow (0.1 inch or more) in Dowagiac usually arrives around November 23, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Dowagiac 1 W, MI, 1.4 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 41 days after the last snow.

Planting calendar for 49047

What to do and when, from the 50% frost dates for Dowagiac, Michigan
WhenWhat to do
February 23 – March 9Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 9 – March 23Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 6 – April 20Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
May 4 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 19Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 27Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 11 onwardPlant 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 49047 is 1 mile from Dowagiac 1 W, MI, which stands at 740 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 49047 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.

Frost dates across Michigan →

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.

ZIP codes measured at the same station

Other zone 6a places in Michigan