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USDA Hardiness Zone 6b

Frost Dates for 48195 — Southgate, Michigan

NOAA 1991–2020 normals from Detroit Metro Airport, MI (631 ft), 7 miles west.

Updated

In Southgate, the last spring frost (32°F) is around April 20 in half of years and has passed by May 8 in nine years out of ten. The first fall frost comes around October 27, as early as October 14 one year in ten, leaving a typical freeze-free season of 188 days (NOAA, Detroit Metro Airport, MI).

Last spring frost
April 20

50% probability

First fall frost
October 27

50% probability

Growing season
188 days

freeze-free, 50%

Hardiness zone
6b

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

First snow
November 20

median, 1991–2020

Last snow
April 15

median, 1991–2020

Winters with snow
100%

15 of 15 observed

Snow per year
53.5"

NOAA normal

Frost risk by date in Southgate

Half of springs at Detroit Metro Airport, MI see their last 32°F night by April 20; only one in ten is past it by April 6, and one in ten still has one after May 8. Planting tender crops after April 28 leaves a 30% risk of a frost on them, after May 2 20%, and after May 8 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 27 in half of years, as early as October 14 one year in ten, and holds off past November 9 one year in ten. A hard freeze of 28°F follows 11 days later, around November 7; in spring the one-in-ten date for 28°F is April 24, 14 days before the 32°F one. The freeze-free season lasts 188 days in a typical year, longer than at 97% of the 172 Michigan stations; it reaches 207 days one year in ten and falls short of 167 one year in ten. On average 120 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 12 days longer, to about May 2, and return around October 15. Severe cold of 16°F or below comes every winter, usually between December 10 and March 11.

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

Freeze probabilities 1991–2020 at Detroit Metro Airport, 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 48195 →Compare Southgate with another place →

Weather by month in Southgate

July is the warmest month at Detroit Metro Airport, MI, averaging 84°F by day and 64°F at night; January is the coldest at 32°F and 19°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 24% of years.

Warmth for growing adds up to 3,114 growing degree days a year (base 50°F), more than at 99% of the 172 Michigan stations. 33% of them (1,042) have built up by the end of June, and July adds the most, 746. Precipitation totals 34.4 inches a year, most in May (3.7") and least in February (2.1"); May to September bring 49% of it.

Monthly normals 1991–2020 at Detroit Metro Airport, MI
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan32192.2100%271
Feb35212.1100%251
Mar46292.4100%2120
Apr59393.397%693
May70503.724%<1329
Jun80603.30%0599
Jul84643.50%0746
Aug81633.30%0691
Sep74563.20%0450
Oct62442.564%2157
Nov49342.6100%1426
Dec37252.3100%243

Monthly normals 1991–2020 at Detroit Metro Airport, MI (631 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, Dearborn, MI, 8 miles north of Southgate, has a last frost 11 days later (May 1), a first frost 12 days earlier (October 15), a season 22 days shorter.

Frost dates for 48185 (Westland) →

When it snows in Southgate, Michigan

The first measurable snow (0.1 inch or more) in Southgate usually arrives around November 20, and the last of the season around April 15. Those are the middle dates across the winters of 1991–2020 at Wyandotte, MI, 1.8 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 5 days after the last snow.

Planting calendar for 48195

What to do and when, from the 50% frost dates for Southgate, Michigan
WhenWhat to do
February 9 – February 23Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 23 – March 9Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 23 – April 6Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 20 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 4Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 13Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 27 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 48195 is 7 miles from Detroit Metro Airport, MI, which stands at 631 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 48180 (Taylor). The 2023 USDA Plant Hardiness Zone Map lists ZIP 48195 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