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USDA Hardiness Zone 5b

Frost Dates for 04039 — Gray, Maine

NOAA 1991–2020 normals from Gray, ME (378 ft), 5 miles east.

Updated

In Gray, the last spring frost (32°F) is around April 28 in half of years and has passed by May 10 in nine years out of ten. The first fall frost comes around October 19, as early as October 5 one year in ten, leaving a typical freeze-free season of 172 days (NOAA, Gray, ME).

Last spring frost
April 28

50% probability

First fall frost
October 19

50% probability

Growing season
172 days

freeze-free, 50%

Hardiness zone
5b

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

First snow
November 20

median, 1991–2020

Last snow
April 12

median, 1991–2020

Winters with snow
100%

25 of 25 observed

Snow per year
84"

NOAA normal

Frost risk by date in Gray

Half of springs at Gray, ME see their last 32°F night by April 28; only one in ten is past it by April 15, and one in ten still has one after May 10. Planting tender crops after May 2 leaves a 30% risk of a frost on them, after May 6 20%, and after May 10 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 52 Maine stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 19 in half of years, as early as October 5 one year in ten, and holds off past November 4 one year in ten. A hard freeze of 28°F follows 13 days later, around November 1; in spring the one-in-ten date for 28°F is April 28, 12 days before the 32°F one. The freeze-free season lasts 172 days in a typical year, longer than at 85% of the 52 Maine stations; it reaches 191 days one year in ten and falls short of 153 one year in ten. On average 144 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 9, and return around October 5. Severe cold of 16°F or below comes every winter, usually between December 2 and March 17.

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

Freeze probabilities 1991–2020 at Gray, 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 04039 →Compare Gray with another place →

Weather by month in Gray

July is the warmest month at Gray, ME, averaging 79°F by day and 60°F at night; January is the coldest at 30°F and 14°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 38% of years.

Warmth for growing adds up to 2,212 growing degree days a year (base 50°F), more than at 77% of the 52 Maine stations. 27% of them (607) have built up by the end of June, and July adds the most, 606. Precipitation totals 50.1 inches a year, most in October (5.4") and least in February (3.3"); May to September bring 40% of it.

Monthly normals 1991–2020 at Gray, ME
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan30143.6100%300
Feb33163.3100%270
Mar41254.0100%265
Apr53344.4100%1128
May64443.638%<1165
Jun73544.70%0410
Jul79603.70%0606
Aug78593.80%0575
Sep70524.32%0333
Oct58415.483%481
Nov46314.7100%1811
Dec35214.6100%291

Monthly normals 1991–2020 at Gray, ME (378 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, Windham 2NW, ME, 6 miles west of Gray, has a last frost 2 days later (April 30), a first frost 1 day later (October 20).

Frost dates for 04062 (Windham) →

When it snows in Gray, Maine

The first measurable snow (0.1 inch or more) in Gray usually arrives around November 20, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Gray, ME, 5 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 16 days after the last snow.

Planting calendar for 04039

What to do and when, from the 50% frost dates for Gray, Maine
WhenWhat to do
February 17 – March 3Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 3 – March 17Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 31 – April 14Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 28 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 27Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 5Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 19 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 04039 is 5 miles from Gray, ME, which stands at 378 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 04096 (Yarmouth). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04039 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