Skip to content

USDA Hardiness Zone 6b

Frost Dates for 49043 — Covert, Michigan

NOAA 1991–2020 normals from S Haven, MI (590 ft), 7 miles north.

Updated

In Covert, the last spring frost (32°F) is around April 17 in half of years and has passed by May 4 in nine years out of ten. The first fall frost comes around November 5, as early as October 24 one year in ten, leaving a typical freeze-free season of 201 days (NOAA, S Haven, MI).

Last spring frost
April 17

50% probability

First fall frost
November 5

50% probability

Growing season
201 days

freeze-free, 50%

Hardiness zone
6b

-5 to 0°F (-20.6 to -17.8°C) coldest night

First snow
November 23

median, 1991–2020

Last snow
March 20

median, 1991–2020

Winters with snow
100%

30 of 30 observed

Snow per year
77.7"

NOAA normal

Frost risk by date in Covert

Half of springs at S Haven, MI see their last 32°F night by April 17; only one in ten is past it by April 3, and one in ten still has one after May 4. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 29 20%, and after May 4 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 62% of the 172 Michigan stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 5 in half of years, as early as October 24 one year in ten, and holds off past November 19 one year in ten. A hard freeze of 28°F follows 9 days later, around November 14; in spring the one-in-ten date for 28°F is April 20, 14 days before the 32°F one. The freeze-free season lasts 201 days in a typical year, the longest of the 172 Michigan stations; it reaches 221 days one year in ten and falls short of 179 one year in ten. On average 108 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 13 days longer, to about April 30, and return around October 25. Severe cold of 16°F or below comes every winter, usually between December 20 and March 7.

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

Freeze probabilities 1991–2020 at S Haven, 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 49043 →Compare Covert with another place →

Weather by month in Covert

July is the warmest month at S Haven, MI, averaging 80°F by day and 66°F at night; January is the coldest at 34°F and 22°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 17% of years.

Warmth for growing adds up to 2,980 growing degree days a year (base 50°F), more than at 95% of the 172 Michigan stations. 31% of them (915) have built up by the end of June, and July adds the most, 707.

Monthly normals 1991–2020 at S Haven, MI
MonthHigh °FLow °F32°F nightNights ≤ 32°FGDD 50°F
Jan3422100%271
Feb3624100%241
Mar4530100%2117
Apr563995%581
May684917%<1283
Jun76600%0533
Jul80660%0707
Aug79640%0668
Sep74570%0464
Oct624828%<1192
Nov493697%1030
Dec3928100%224

Monthly normals 1991–2020 at S Haven, MI (590 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, Benton Harbor Airport, MI, 14 miles southwest of Covert, has a last frost 18 days later (May 5), a first frost 21 days earlier (October 15), a season 40 days shorter.

Frost dates for 49022 (Benton Harbor) →

When it snows in Covert, Michigan

The first measurable snow (0.1 inch or more) in Covert usually arrives around November 23, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Benton Harbor Airport, MI, 14.4 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 28 days after the last snow.

Planting calendar for 49043

What to do and when, from the 50% frost dates for Covert, Michigan
WhenWhat to do
February 6 – February 20Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 20 – March 6Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 20 – April 3Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 17 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 13Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 22Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 5 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 49043 is 7 miles from S Haven, MI, which stands at 590 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 49090 (South Haven). The 2023 USDA Plant Hardiness Zone Map lists ZIP 49043 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.

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 6b places in Michigan