Photo: User:Smallbones on English Wikipedia. · Public domainPrecipitation in Thornbury Township tops that of 75% of U.S. towns: 48 inches a year
Midwinter brings lows of about 24°. Compared with 1901–2000, the average now sits 1.9° higher. Long walks are most pleasant from April to June and September to October, when afternoons reach 64–82°.
A year in Thornbury Township at a glance
Each month’s typical high and low, and what it brings.
What stands out about Thornbury Township’s climate
Compared with towns across the U.S., with Thornbury Township’s place in Pennsylvania beside it.
What a year in Thornbury Township feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 209 frost-free days a year
In half of years the last 32° night comes by April 7 and the first by November 4. Frost and day counts come from NOAA’s station at Wilmington Porter Rsch, DE, 10 miles from the town’s center, 100 ft lower.
The 2023 USDA map puts Thornbury 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°
90° days by month
Average days at 90° or more
About 12 inches of snow a winter
Snow, measured at Wilmington Porter Rsch, DE, falls mostly in January. Precipitation (rain plus melted snow) adds up to 48 inches a year; September is the wettest month and February the driest. Rain or snow falls on about 113 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Thornbury Township
84% of the work is heating. Months averaging under 55° run from November through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Wilmington Porter Rsch, DE.
Living with Thornbury Township’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
209 frost-free days in zone 7a. The last frost comes by Apr 7 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 4.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 9.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Thornbury Township from natural hazards, river flooding is the largest share (61%); heat waves, cold waves, winter storms and ice storms together are 14%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Thornbury Township and its neighbors
Every town next door is within a degree of Thornbury Township in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Thornbury 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.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Thornbury Township, PA | 24° | 86° | 48" | 12" |
| Scottsburg, IN | 23° | 87° | 48" | 12" |
| Paris, KY | 24° | 87° | 49" | 15" |
| Huntington, WV | 25° | 87° | 46" | 10" |
| Mount Vernon, IL | 23° | 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.
Warmer than it used to be
The last 30 years in Thornbury Township averaged 1.9° warmer than the 1900s. The biggest change is in December (+3.4°).
A bigger shift than in 84% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Thornbury Township compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Thornbury Township’s place among Pennsylvania’s.
Thornbury Township weather by month
Highs, lows and precipitation from NOAA’s grid at Thornbury Township’s center; snow, wet days and snow on the ground from Wilmington Porter Rsch, DE. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 40° | 24° | 3.5" | 5.3" | 10 | 24° – 39° |
| February | 43° | 25° | 2.8" | 4.0" | 9 | 24° – 42° |
| March | 51° | 32° | 4.2" | 1.8" | 11 | 36° – 50° |
| April | 64° | 41° | 3.7" | 0.0" | 10 | 48° – 58° |
| May | 73° | 51° | 3.7" | 0.0" | 11 | 58° – 68° |
| June | 82° | 61° | 4.4" | 0.0" | 10 | 68° – 75° |
| July | 86° | 66° | 4.7" | 0.0" | 9 | 72° – 80° |
| August | 85° | 64° | 4.5" | 0.0" | 9 | 70° – 78° |
| September | 78° | 57° | 4.8" | 0.0" | 9 | 64° – 71° |
| October | 66° | 46° | 4.1" | 0.0" | 8 | 51° – 63° |
| November | 55° | 36° | 3.3" | 0.1" | 8 | 39° – 50° |
| December | 45° | 28° | 4.1" | 0.8" | 10 | 29° – 49° |
| Year | 64° | 44° | 47.8" | 12.0" | 113 |
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°. September is the most reliable, staying within 7°.
Where Thornbury 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 Thornbury Township’s center.
- Snow: Wilmington Porter Rsch, DE.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Wilmington Porter Rsch, DE, 10 miles from the town’s center, 100 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 Thornbury Township’s climate
What is the weather like in Thornbury Township?
A typical July afternoon reaches 86°, a January night drops to 24°, and about 12 inches of snow falls in a normal winter. Milder January nights than 58% of U.S. towns; hotter July afternoons than 58% of U.S. towns.
How cold does it get in Thornbury Township in winter?
January nights average 24°. About 87 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 24°.
How much snow does Thornbury Township get?
About 12 inches in a normal winter at Wilmington Porter Rsch, DE, most of it in January.
How hot does it get in Thornbury Township?
July, with a typical high of 86° and a low of 66°. About 17 days a year reach 90° (Wilmington Porter Rsch, DE).
When is the first and last frost in Thornbury Township?
In half of years the last spring frost (32°) comes by April 7 and the first fall frost by November 4, about 209 frost-free days, at Wilmington Porter Rsch, DE.
What growing zone is Thornbury 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 Thornbury 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 Thornbury Township getting warmer?
Yes: 1991–2020 averaged 1.9° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 84% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Thornbury Township.
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.