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Shirley Municipal BuildingPhoto: Bob Burkhardt · CC BY 3.0
Climate in Shirley · NOAA 1991–2020 normals

Shirley’s winters are colder and snowier than most of the U.S.

A typical July afternoon reaches 84°, a January night drops to 15°, and about 53 inches of snow falls in a normal winter.

More snow than 85% of U.S. towns#110Snowiest  of 321 in MA
Colder January nights than 84% of U.S. towns#40 coldest of 324 in MA
All MA rankings →

A year in Shirley at a glance

Each month’s typical high and low, and what it brings.

Jan35°15° 15" snow
Feb37°17° 15" snow
Mar46°25° 10" snow
Apr59°35° Last frost ~Apr 29
May70°46° 1 day 90°+
Jun78°55° 3 days 90°+
Jul84°61° 7 days 90°+
Aug82°59° 4 days 90°+
Sep75°51° 1 day 90°+
Oct62°39° First frost ~Oct 11Wettest
Nov now50°30°
Dec40°22° 11" snow

What stands out about Shirley’s climate

Compared with towns across the U.S., with Shirley’s place in Massachusetts beside it.

A normal year

What a year in Shirley feels like

Typical highs and lows by season and by month, from NOAA’s 30-year normals.

Winter
37° / 18°
14 days with 1"+ of snow
Spring
58° / 35°
Last frost around Apr 29
Summer
81° / 59°
15 days reach 90°
Fall
62° / 40°
First frost around Oct 11
Best months to be outsideMayJunJulAugSepHighs of 62–84° and lows of 40° or more
Frost, heat & the growing season

About 164 frost-free days a year

In half of years the last 32° night comes by April 29 and the first by October 11. Frost and day counts come from NOAA’s station at Fitchburg Muni Airport, 6 miles from the town’s center, at about the same height.

137
nights at or below 32° in a normal year
152nd most of 323 in Massachusetts
More freezing nights than 74% of U.S. towns
5
nights at or below 0°
126th most of 323 in Massachusetts
More nights at or below 0° than 67% of U.S. towns
15
days that reach 90°
247th fewest of 323 in Massachusetts
Fewer 90° days than 60% of U.S. towns
<1
days that reach 100°
148th fewest of 323 in Massachusetts
Fewer 100° days than 68% of U.S. towns
6aUSDA zone
Plant hardiness zone 6a

The 2023 USDA map puts Shirley’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −6°. Plant labels use the zone; frost dates tell you when to plant.

Freezing nights by month

Average nights at or below 32°

29
JFMAMJJASOND

90° days by month

Average days at 90° or more

6.5
JFMAMJJASOND
Rain & snow

About 53 inches of snow a winter

Snow, measured at Nashua 2 Nnw, NH, is heaviest from January through February, about 15 inches a month. Precipitation (rain plus melted snow) adds up to 47 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 120 days a year.

47"
Rain + melted snow a year
225th wettest of 324 in Massachusetts
Wetter than 72% of U.S. towns
53"
Snow in a normal winter
110th snowiest of 321 in Massachusetts
More snow than 85% of U.S. towns

Rain + melted snow by month

Inches of water

4.7"
JFMAMJJASOND

Snowfall by month

Inches of snow

15"
JFMAMJJASOND
Heating & cooling

Heating and cooling a home in Shirley

91% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.

6,483 heating degree daysMore heating than 78% of U.S. towns
641 cooling degree daysLess cooling than 73% of U.S. towns

Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Fitchburg Muni Airport.

Living here

Living with Shirley’s climate

What the numbers mean for a garden, a free afternoon and a bad-weather day.

The garden window

164 frost-free days in zone 6a. The last frost comes by Apr 29 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 11.

Get outside

Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 27 miles of trails are waiting.

Parks & trails →
Storms and extremes

Of the yearly building losses FEMA expects in Shirley from natural hazards, river flooding is the largest share (63%); heat waves, cold waves, winter storms and ice storms together are 11%. Normals are averages; the hazards page covers the extremes.

Natural hazards →
Next door

Shirley and its neighbors

Every town next door is within a degree of Shirley in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.

Pepperell: January low 15°, July high 84°Dunstable: January low 16°, July high 84°Westford: January low 16°, July high 84°Tyngsborough: January low 16°, July high 84°Littleton: January low 16°, July high 84°Lancaster: January low 16°, July high 84°Boxborough: January low 16°, July high 84°Bolton: January low 16°, July high 84°Fitchburg: January low 15°, July high 82°Leominster: January low 15°, July high 83°Townsend: January low 15°, July high 83°Ashby: January low 14°, July high 81°Groton: January low 16°, July high 84°Ayer: January low 16°, July high 84°Devens: January low 16°, July high 84°Harvard: January low 16°, July high 84°Lunenburg: January low 15°, July high 83°Shirley: January low 15°, July high 84°ShirleyGrotonAyerDevensHarvardLunenburg
ColderMilder14° to 16°
Lunenburg15.0° about the same
Shirley15.2°
Devens15.5° about the same
Groton15.6° about the same
Harvard15.6° about the same
Ayer15.7° about the same

Climates most like Shirley’s, farther away

TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.

TownJan. lowJuly highPrecip.Snow
Shirley, MA15°84°47"53"
Crawford, NY17°83°46"44"
Franklin, PA19°83°45"54"
Newton, NJ18°83°47"39"
Ontario, OH17°82°42"49"

Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.

Then and now

Warmer than it used to be

The last 30 years in Shirley averaged 1.7° warmer than the 1900s. The biggest change is in December (+3.2°).

+1.7°1991–2020 vs. 1901–2000

A bigger shift than in 75% of U.S. towns.

Winter+2.5°now 28°, was 25°
Spring+1.3°now 47°, was 46°
Summer+1.7°now 70°, was 68°
Fall+1.5°now 51°, was 50°

Change by month

JanFebMarAprMayJunJulAugSepOctNovDec

The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.

Compared with other towns

How Shirley compares

Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Shirley’s place among Massachusetts’.

Summer heat84° July high
Cooler July afternoons than 61% of U.S. towns264th coolest of 324 in Massachusetts
Winter cold15° January low
Colder January nights than 84% of U.S. towns40th coldest of 324 in Massachusetts
Precipitation47" a year
Wetter than 72% of U.S. towns225th wettest of 324 in Massachusetts
Snow53" a winter
More snow than 85% of U.S. towns110th snowiest of 321 in Massachusetts
Hot days15 days at 90°+
Fewer 90° days than 60% of U.S. towns247th fewest of 323 in Massachusetts
Freezing nights137 a year
More freezing nights than 74% of U.S. towns152nd most of 323 in Massachusetts
Growing season164 frost-free days
A shorter frost-free season than 79% of U.S. towns95th shortest of 323 in Massachusetts
Month by month

Shirley weather by month

Highs, lows and precipitation from NOAA’s grid at Shirley’s center; snow, wet days and snow on the ground from Nashua 2 Nnw, NH. 1991–2020 normals.

MonthHighLowRain + meltSnowWet days30-yr range
January35°15°3.4"14.7"915° – 32°
February37°17°3.3"14.5"813° – 34°
March46°25°4.2"10.1"929° – 44°
April59°35°4.2"0.7"1143° – 52°
May70°46°3.7"0.0"1252° – 64°
June78°55°4.3"0.0"1164° – 70°
July84°61°3.6"0.0"1068° – 76°
August82°59°3.6"0.0"967° – 74°
September75°51°4.1"0.0"960° – 67°
October62°39°4.7"0.0"1147° – 57°
November50°30°3.9"1.7"1035° – 45°
December40°22°4.4"11.2"1024° – 40°
Year60°38°47.4"52.9"120
Year to year

How much a month can swing

A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 13° to 34°. June is the most reliable, staying within 6°.

Coldest to warmest month in 30 yearsNormal
Sources

Where Shirley’s numbers come from

Normals are 30-year averages, not a forecast. How TownRatings reads climate data →

  • Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Shirley’s center.
  • Snow: Nashua 2 Nnw, NH.
  • Frost, freezing nights, 90° and 100° days, heating and cooling: Fitchburg Muni Airport, 6 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
  • Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
  • Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
  • Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).

Common questions about Shirley’s climate

What is the weather like in Shirley?

A typical July afternoon reaches 84°, a January night drops to 15°, and about 53 inches of snow falls in a normal winter. Colder January nights than 84% of U.S. towns; cooler July afternoons than 61% of U.S. towns.

How cold does it get in Shirley in winter?

January nights average 15°. About 137 nights a year reach 32° or below and 5 reach 0° or below. In the coldest January of the last 30 years the month averaged 15°.

How much snow does Shirley get?

About 53 inches in a normal winter at Nashua 2 Nnw, NH, heaviest from January through February, about 15 inches a month.

How hot does it get in Shirley?

July, with a typical high of 84° and a low of 61°. About 15 days a year reach 90° (Fitchburg Muni Airport).

When is the first and last frost in Shirley?

In half of years the last spring frost (32°) comes by April 29 and the first fall frost by October 11, about 164 frost-free days, at Fitchburg Muni Airport.

What growing zone is Shirley in?

Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −6°.

What is the best time of year to visit Shirley?

By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.

Is Shirley getting warmer?

Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 75% of U.S. towns.

Neighbors talk weather

Gardens, snow, and the best days of the year in Shirley.

Town Square →
Ask your neighbors

Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.