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USDA Hardiness Zone 5a

Frost Dates for 55426 — St Louis Park, Minnesota

NOAA 1991–2020 normals from New Hope, MN (910 ft), 4 miles north.

Updated

In St Louis Park, the last spring frost (32°F) is around April 29 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 12, as early as September 29 one year in ten, leaving a typical freeze-free season of 163 days (NOAA, New Hope, MN).

Last spring frost
April 29

50% probability

First fall frost
October 12

50% probability

Growing season
163 days

freeze-free, 50%

Hardiness zone
5a

-20 to -15°F (-28.9 to -26.1°C) coldest night

First snow
November 7

median, 1991–2020

Last snow
April 11

median, 1991–2020

Winters with snow
100%

29 of 29 observed

Snow per year
54.3"

NOAA normal

Frost risk by date in St Louis Park

Half of springs at New Hope, MN see their last 32°F night by April 29; only one in ten is past it by April 15, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 61% of the 142 Minnesota stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 12 in half of years, as early as September 29 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 10 days later, around October 22; in spring the one-in-ten date for 28°F is May 1, 11 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 84% of the 142 Minnesota stations; it reaches 182 days one year in ten and falls short of 144 one year in ten. On average 156 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 9 days longer, to about May 8, and return around October 1. Severe cold of 16°F or below comes every winter, usually between November 16 and March 26.

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

Freeze probabilities 1991–2020 at New Hope, MN, 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 55426 →Compare St Louis Park with another place →

Weather by month in St Louis Park

July is the warmest month at New Hope, MN, averaging 82°F by day and 63°F at night; January is the coldest at 24°F and 7°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 41% of years.

Warmth for growing adds up to 2,711 growing degree days a year (base 50°F), more than at 85% of the 142 Minnesota stations. 33% of them (904) have built up by the end of June, and July adds the most, 704. Precipitation totals 34.8 inches a year, most in June (4.6") and least in January (1.0"); May to September bring 61% of it.

Monthly normals 1991–2020 at New Hope, MN
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan2471.0100%310
Feb29111.0100%270
Mar42231.9100%2510
Apr57353.3100%1269
May69484.541%1281
Jun78584.60%0545
Jul82634.50%0704
Aug80614.20%0628
Sep72523.513%<1372
Oct57393.098%895
Nov41261.9100%239
Dec29141.4100%300

Monthly normals 1991–2020 at New Hope, MN (910 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, Lower St Anthony Falls, MN, 7 miles east of St Louis Park and 156 feet lower, has a last frost 6 days earlier (April 23), a first frost 4 days later (October 16), a season 12 days longer.

Frost dates for 55407 (Minneapolis) →

When it snows in St Louis Park, Minnesota

The first measurable snow (0.1 inch or more) in St Louis Park usually arrives around November 7, and the last of the season around April 11. Those are the middle dates across the winters of 1991–2020 at New Hope, MN, 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 18 days after the last snow.

Planting calendar for 55426

What to do and when, from the 50% frost dates for St Louis Park, Minnesota
WhenWhat to do
February 18 – March 4Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 4 – March 18Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 1 – April 15Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 29 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 20Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 28Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 12 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 55426 is 4 miles from New Hope, MN, which stands at 910 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 11 other ZIP codes share the station; its figures are presented in full for 55416 (St Louis Park). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55426 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Minnesota →

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 5a places in Minnesota