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USDA Hardiness Zone 5b

Frost Dates for 04076 — Shapleigh, Maine

NOAA 1991–2020 normals from Sanford 2 NNW, ME (289 ft), 7 miles southeast.

Updated

In Shapleigh, the last spring frost (32°F) is around May 16 in half of years and has passed by May 29 in nine years out of ten. The first fall frost comes around September 30, as early as September 18 one year in ten, leaving a typical freeze-free season of 136 days (NOAA, Sanford 2 NNW, ME).

Last spring frost
May 16

50% probability

First fall frost
September 30

50% probability

Growing season
136 days

freeze-free, 50%

Hardiness zone
5b

-15 to -10°F (-26.1 to -23.3°C) coldest night

First snow
December 4

median, 1991–2020

Last snow
March 24

median, 1991–2020

Winters with snow
100%

28 of 28 observed

Snow per year
—

NOAA normal

Frost risk by date in Shapleigh

Half of springs at Sanford 2 NNW, ME see their last 32°F night by May 16; only one in ten is past it by May 2, and one in ten still has one after May 29. Planting tender crops after May 21 leaves a 30% risk of a frost on them, after May 24 20%, and after May 29 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 33% of the 52 Maine stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 30 in half of years, as early as September 18 one year in ten, and holds off past October 10 one year in ten. A hard freeze of 28°F follows 7 days later, around October 7; in spring the one-in-ten date for 28°F is May 17, 12 days before the 32°F one. The freeze-free season lasts 136 days in a typical year, shorter than at 83% of the 52 Maine stations; it reaches 153 days one year in ten and falls short of 118 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 10 days longer, to about May 26, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 16 and March 29.

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

Freeze probabilities 1991–2020 at Sanford 2 NNW, ME, 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 04076 →Compare Shapleigh with another place →

Weather by month in Shapleigh

July is the warmest month at Sanford 2 NNW, ME, averaging 81°F by day and 56°F at night; January is the coldest at 32°F and 10°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 2,120 growing degree days a year (base 50°F), more than at 65% of the 52 Maine stations. 29% of them (616) have built up by the end of June, and July adds the most, 580. Precipitation totals 51.4 inches a year, most in October (5.4") and least in February (3.6"); May to September bring 39% of it.

Monthly normals 1991–2020 at Sanford 2 NNW, ME
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan32103.7100%300
Feb35113.6100%270
Mar44204.7100%264
Apr57304.6100%1440
May68413.894%2170
Jun76514.67%0402
Jul81564.00%0580
Aug80553.90%0539
Sep73473.852%1307
Oct61365.4100%869
Nov48274.5100%209
Dec37174.8100%280

Monthly normals 1991–2020 at Sanford 2 NNW, ME (289 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, Hollis, ME, 11 miles northeast of Shapleigh, has a last frost 2 days earlier (May 14), the same first-frost date.

Frost dates for 04042 (Hollis Center) →

When it snows in Shapleigh, Maine

The first measurable snow (0.1 inch or more) in Shapleigh usually arrives around December 4, and the last of the season around March 24. Those are the middle dates across the winters of 1991–2020 at Sanford 2 NNW, ME, 7.4 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 53 days after the last snow.

Planting calendar for 04076

What to do and when, from the 50% frost dates for Shapleigh, Maine
WhenWhat to do
March 7 – March 21Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 21 – April 4Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 18 – May 2Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
May 16 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 8Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 16Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
September 30 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 04076 is 7 miles from Sanford 2 NNW, ME, which stands at 289 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 7 other ZIP codes share the station; its figures are presented in full for 04073 (Sanford). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04076 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Maine →

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 5b places in Maine