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Radnor Station PennsylvaniaPhoto: Lucius Kwok · CC BY 2.5
Climate in Radnor Township · NOAA 1991–2020 normals

Radnor Township’s winters are milder and less snowy than most of the U.S.

A typical July afternoon reaches 87°, a January night drops to 24°, and about 8 inches of snow falls in a normal winter.

Less snow than 67% of U.S. towns#19Least snow  of 993 in PA
Milder January nights than 60% of U.S. towns#34Mildest winters  of 1,005 in PA
All PA rankings →

A year in Radnor Township at a glance

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

Jan40°24°
Feb43°25°
Mar51°32°
Apr63°42° Last frost ~Apr 81 day 90°+
May73°52° 3 days 90°+
Jun82°61° 7 days 90°+
Jul87°67° 15 days 90°+Wettest
Aug84°65° 10 days 90°+
Sep78°58° 4 days 90°+
Oct66°46° First frost ~Oct 31
Nov now55°37°
Dec45°29°

What stands out about Radnor Township’s climate

Compared with towns across the U.S., with Radnor Township’s place in Pennsylvania beside it.

A normal year

What a year in Radnor Township feels like

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

Winter
43° / 26°
3 days with 1"+ of snow
Spring
63° / 42°
Last frost around Apr 8
Summer
84° / 64°
39 days reach 90°
Fall
66° / 47°
First frost around Oct 31
Best months to be outsideAprMayJunSepOctHighs of 62–84° and lows of 40° or more
Frost, heat & the growing season

About 203 frost-free days a year

In half of years the last 32° night comes by April 8 and the first by October 31. Frost and day counts come from NOAA’s station at Norristown, PA, 6 miles from the town’s center, 310 ft lower.

107
nights at or below 32° in a normal year
132nd fewest of 1,005 in Pennsylvania
Fewer freezing nights than 56% of U.S. towns
<1
nights at or below 0°
33rd fewest of 1,005 in Pennsylvania
Fewer nights at or below 0° than 66% of U.S. towns
39
days that reach 90°
2nd most of 1,005 in Pennsylvania
More 90° days than 69% of U.S. towns
2
days that reach 100°
2nd most of 1,005 in Pennsylvania
More 100° days than 79% of U.S. towns
7aUSDA zone
Plant hardiness zone 7a

The 2023 USDA map puts Radnor Township’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 4°. Plant labels use the zone; frost dates tell you when to plant.

Freezing nights by month

Average nights at or below 32°

26
JFMAMJJASOND

90° days by month

Average days at 90° or more

15
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Rain & snow

About 8 inches of snow a winter

Snow, measured at Conshohocken, PA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 48 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 111 days a year.

48"
Rain + melted snow a year
198th wettest of 1,005 in Pennsylvania
Wetter than 77% of U.S. towns
7.6"
Snow in a normal winter
19th least snowy of 993 in Pennsylvania
Less snow than 67% of U.S. towns
9 days
With 1"+ of snow on the ground
The fewest of 821 in Pennsylvania
Fewer days with snow on the ground than 62% of U.S. towns

Rain + melted snow by month

Inches of water

4.8"
JFMAMJJASOND

Snowfall by month

Inches of snow

3"
JFMAMJJASOND
Heating & cooling

Heating and cooling a home in Radnor Township

80% of the work is heating. Months averaging under 55° run from November through April.

4,869 heating degree daysLess heating than 59% of U.S. towns
1,254 cooling degree daysMore cooling than 66% 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 Norristown, PA.

Living here

Living with Radnor Township’s climate

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

The garden window

203 frost-free days in zone 7a. The last frost comes by Apr 8 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 31.

Get outside

Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 15 miles of trails are waiting.

Parks & trails →
Storms and extremes

Of the yearly building losses FEMA expects in Radnor Township from natural hazards, river flooding is the largest share (58%); heat waves, cold waves, winter storms and ice storms together are 17%. Normals are averages; the hazards page covers the extremes.

Natural hazards →
Next door

Radnor Township and its neighbors

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

Broomall: January low 24°, July high 87°Penn Wynne: January low 25°, July high 87°Upper Darby Township: January low 26°, July high 87°Drexel Hill: January low 25°, July high 87°Bryn Mawr: January low 24°, July high 87°Springfield Township: January low 25°, July high 87°Willistown Township: January low 23°, July high 86°Edgmont Township: January low 24°, July high 87°Easttown Township: January low 23°, July high 86°Upper Providence Township: January low 25°, July high 87°Philadelphia: January low 25°, July high 87°Bala Cynwyd: January low 25°, July high 87°West Conshohocken: January low 24°, July high 87°Whitemarsh Township: January low 24°, July high 87°Conshohocken: January low 24°, July high 87°Nether Providence Township: January low 26°, July high 88°King of Prussia: January low 23°, July high 87°West Norriton Township: January low 23°, July high 87°Schuylkill Township: January low 23°, July high 88°Bridgeport: January low 23°, July high 88°Swedeland: January low 23°, July high 88°Plymouth Township: January low 24°, July high 88°Lower Providence Township: January low 23°, July high 87°Swedesburg: January low 24°, July high 88°Berwyn: January low 23°, July high 86°Paoli: January low 23°, July high 87°East Whiteland Township: January low 23°, July high 87°Devon: January low 23°, July high 87°St. Davids: January low 24°, July high 87°Haverford Township: January low 25°, July high 87°Newtown Township: January low 24°, July high 87°Lower Merion Township: January low 24°, July high 87°Marple Township: January low 24°, July high 87°Upper Merion Township: January low 23°, July high 87°Tredyffrin Township: January low 23°, July high 87°Wayne: January low 24°, July high 86°Radnor Township: January low 24°, July high 87°Radnor TownshipHaverford TownshipNewtown TownshipLower Merion TownshipMarple TownshipUpper Merion TownshipTredyffrin TownshipWayne
ColderMilder23° to 26°
Upper Merion Township23.2° about the same
Tredyffrin Township23.3° about the same
Wayne23.6° about the same
Radnor Township24.0°
Newtown Township24.2° about the same
Lower Merion Township24.3° about the same
Marple Township24.3° about the same
Haverford Township24.7° about the same

Climates most like Radnor Township’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
Radnor Township, PA24°87°48"7.6"
Danville, KY25°86°49"7.4"
Washington, IN22°87°48"9.2"
Elizabethton, TN26°86°47"6.0"
Huntington, WV25°87°46"10"

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 Radnor Township averaged 2.0° warmer than the 1900s. The biggest change is in December (+3.5°).

+2.0°1991–2020 vs. 1901–2000

A bigger shift than in 90% of U.S. towns.

Winter+2.8°now 34°, was 32°
Spring+1.6°now 52°, was 51°
Summer+1.9°now 74°, was 72°
Fall+1.7°now 56°, was 55°

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 Radnor Township compares

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

Summer heat87° July high
Hotter July afternoons than 59% of U.S. towns112th hottest of 1,005 in Pennsylvania
Winter cold24° January low
Milder January nights than 60% of U.S. towns34th mildest of 1,005 in Pennsylvania
Precipitation48" a year
Wetter than 77% of U.S. towns198th wettest of 1,005 in Pennsylvania
Snow7.6" a winter
Less snow than 67% of U.S. towns19th least snowy of 993 in Pennsylvania
Hot days39 days at 90°+
More 90° days than 69% of U.S. towns2nd most of 1,005 in Pennsylvania
Freezing nights107 a year
Fewer freezing nights than 56% of U.S. towns132nd fewest of 1,005 in Pennsylvania
Growing season203 frost-free days
A longer frost-free season than 69% of U.S. towns87th longest of 1,005 in Pennsylvania
Month by month

Radnor Township weather by month

Highs, lows and precipitation from NOAA’s grid at Radnor Township’s center; snow, wet days and snow on the ground from Conshohocken, PA. 1991–2020 normals.

MonthHighLowRain + meltSnowWet daysSnow on ground30-yr range
January40°24°3.5"2.7"9324° – 39°
February43°25°2.9"2.4"9323° – 41°
March51°32°4.2"0.6"10236° – 50°
April63°42°3.7"0.1"11049° – 58°
May73°52°3.9"0.0"11058° – 68°
June82°61°4.4"0.0"9068° – 76°
July87°67°4.8"0.0"9072° – 80°
August84°65°4.5"0.0"9070° – 78°
September78°58°4.7"0.0"8064° – 72°
October66°46°4.1"0.0"9051° – 63°
November55°37°3.4"0.2"8040° – 50°
December45°29°4.3"1.6"10129° – 49°
Year64°45°48.2"7.6"1119
Year to year

How much a month can swing

A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 29° to 49°. June is the most reliable, staying within 7°.

Coldest to warmest month in 30 yearsNormal
Sources

Where Radnor Township’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 Radnor Township’s center.
  • Snow: Conshohocken, PA.
  • Frost, freezing nights, 90° and 100° days, heating and cooling: Norristown, PA, 6 miles from the town’s center, 310 ft lower; 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 Radnor Township’s climate

What is the weather like in Radnor Township?

A typical July afternoon reaches 87°, a January night drops to 24°, and about 8 inches of snow falls in a normal winter. Milder January nights than 60% of U.S. towns; hotter July afternoons than 59% of U.S. towns.

How cold does it get in Radnor Township in winter?

January nights average 24°. About 107 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 24°.

How much snow does Radnor Township get?

About 7.6 inches in a normal winter at Conshohocken, PA, most of it in January, with snow on the ground about 9 days a year.

How hot does it get in Radnor Township?

July, with a typical high of 87° and a low of 67°. About 39 days a year reach 90° and 2 reach 100° (Norristown, PA).

When is the first and last frost in Radnor Township?

In half of years the last spring frost (32°) comes by April 8 and the first fall frost by October 31, about 203 frost-free days, at Norristown, PA.

What growing zone is Radnor Township in?

Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 4°.

What is the best time of year to visit Radnor Township?

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

Is Radnor Township getting warmer?

Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 90% of U.S. towns.

Neighbors talk weather

Gardens, snow, and the best days of the year in Radnor Township.

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.