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USDA Hardiness Zone 6b

Frost Dates for 01590 — Sutton, Massachusetts

NOAA 1991–2020 normals from Buffumville Lake, MA (520 ft), 8 miles west.

Updated

In Sutton, the last spring frost (32°F) is around May 1 in half of years and has passed by May 13 in nine years out of ten. The first fall frost comes around October 10, as early as September 28 one year in ten, leaving a typical freeze-free season of 162 days (NOAA, Buffumville Lake, MA).

Last spring frost
May 1

50% probability

First fall frost
October 10

50% probability

Growing season
162 days

freeze-free, 50%

Hardiness zone
6b

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

First snow
December 6

median, 1991–2020

Last snow
March 20

median, 1991–2020

Winters with snow
100%

28 of 28 observed

Snow per year
48.3"

NOAA normal

Frost risk by date in Sutton

Half of springs at Buffumville Lake, MA see their last 32°F night by May 1; only one in ten is past it by April 21, and one in ten still has one after May 13. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 8 20%, and after May 13 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 10 in half of years, as early as September 28 one year in ten, and holds off past October 27 one year in ten. A hard freeze of 28°F follows 12 days later, around October 22; in spring the one-in-ten date for 28°F is May 1, 12 days before the 32°F one. The freeze-free season lasts 162 days in a typical year, shorter than at 66% of the 71 Massachusetts stations; it reaches 180 days one year in ten and falls short of 143 one year in ten. On average 153 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 12, and return around October 2. Severe cold of 16°F or below comes every winter, usually between December 1 and March 16.

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

Freeze probabilities 1991–2020 at Buffumville Lake, MA, 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 01590 →Compare Sutton with another place →

Weather by month in Sutton

July is the warmest month at Buffumville Lake, MA, averaging 83°F by day and 60°F at night; January is the coldest at 34°F and 15°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 54% of years.

Warmth for growing adds up to 2,532 growing degree days a year (base 50°F), fewer than at 65% of the 71 Massachusetts stations. 30% of them (772) have built up by the end of June, and July adds the most, 663. Precipitation totals 48.9 inches a year, most in October (4.8") and least in February (3.2"); May to September bring 41% of it.

Monthly normals 1991–2020 at Buffumville Lake, MA
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan34153.8100%300
Feb37153.2100%270
Mar45244.4100%266
Apr57344.3100%1349
May69453.654%2237
Jun77554.10%0479
Jul83603.90%0663
Aug81594.20%0609
Sep74514.114%<1373
Oct61394.894%899
Nov50303.9100%2015
Dec39214.6100%281

Monthly normals 1991–2020 at Buffumville Lake, MA (520 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, Worcester Regional Airport, MA, 11 miles northwest of Sutton and 480 feet higher, has a last frost 8 days earlier (April 23), a first frost 11 days later (October 21), a season 19 days longer.

Frost dates for 01604 (Worcester) →

When it snows in Sutton, Massachusetts

The first measurable snow (0.1 inch or more) in Sutton usually arrives around December 6, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Northbridge 2, MA, 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 42 days after the last snow.

Planting calendar for 01590

What to do and when, from the 50% frost dates for Sutton, Massachusetts
WhenWhat to do
February 20 – March 6Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 6 – March 20Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
April 3 – April 17Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
May 1 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 18Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by September 26Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 10 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 01590 is 8 miles from Buffumville Lake, MA, which stands at 520 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 01570 (Webster). The 2023 USDA Plant Hardiness Zone Map lists ZIP 01590 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 Massachusetts →

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 Massachusetts