Willow Grove, Pennsylvania climate: Normal weather by month, frost dates and records
Willow Grove's normal year runs from 24°F January nights to 85°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.2°C, January lows of −4°C, July highs of 30°C.
- NOAA stationWillow Grove Naval Air Station
- Station IDUSW00014793
- Location40.20°N 75.15°W
- Elevation361 ft (110 m)
- From the center4 miles
- Population (census place)13,919
On October 23, the normal high in Willow Grove is 62°F and the normal low 44°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Willow Grove.
- Jan 40° 24°
- Feb 43° 26°
- Mar 51° 32°
- Apr 63° 42°
- May 72° 52°
- Jun 81° 61°
- Jul 85° 67°
- Aug 83° 65°
- Sep 76° 58°
- Oct 64° 47°
- Nov 54° 37°
- Dec 44° 30°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Willow Grove each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 24°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 40°F | 24°F | 31.9°F | – | <1 | 24 | 9 h 40 min |
| February | 43°F | 26°F | 34.6°F | – | <1 | 21 | 10 h 40 min |
| March | 51°F | 32°F | 41.8°F | – | <1 | 15 | 11 h 50 min |
| April | 63°F | 42°F | 52.4°F | – | 1 | 3 | 13 h 10 min |
| May | 72°F | 52°F | 62.2°F | – | 2 | <1 | 14 h 20 min |
| June | 81°F | 61°F | 71.1°F | – | 5 | <1 | 15 h |
| July | 85°F | 67°F | 76.0°F | – | 8 | <1 | 14 h 50 min |
| August | 83°F | 65°F | 73.9°F | – | 6 | <1 | 13 h 50 min |
| September | 76°F | 58°F | 66.8°F | – | 1 | <1 | 12 h 30 min |
| October | 64°F | 47°F | 55.5°F | – | <1 | 1 | 11 h 10 min |
| November | 54°F | 37°F | 45.2°F | – | <1 | 9 | 10 h |
| December | 44°F | 30°F | 36.6°F | – | <1 | 19 | 9 h 20 min |
| Year (annual) | 63°F | 45°F | 54.0°F | – | 22 | 92 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 4°C | −4°C | −0.1°C |
| February | 6°C | −3°C | 1.4°C |
| March | 11°C | 0°C | 5.4°C |
| April | 17°C | 6°C | 11.3°C |
| May | 22°C | 11°C | 16.8°C |
| June | 27°C | 16°C | 21.7°C |
| July | 30°C | 19°C | 24.4°C |
| August | 28°C | 18°C | 23.3°C |
| September | 24°C | 14°C | 19.3°C |
| October | 18°C | 8°C | 13.1°C |
| November | 12°C | 3°C | 7.3°C |
| December | 6°C | −1°C | 2.6°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Neshaminy Falls (11 miles away), gets 20 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014793; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Willow Grove?
Normal highs sit between 65°F and 85°F in May, June, August and September.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014793.
When is the last frost in Willow Grove?
In Willow Grove, the last spring frost (32°F) comes after April 11 in half of years and after April 27 in one year in ten; the first autumn frost comes before November 1 in half of years and before October 17 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 111 year in 10 after April 27; 9 in 10 after March 29
- First autumn frost, half of years before
- November 11 year in 10 before October 17; 9 in 10 before November 17
NOAA puts the median frost-free season at 205 days, and the season without a hard freeze (28°F) at 229 days.
A hard freeze (28°F) comes after March 30 in half of springs and before November 13 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Willow Grove in zone 7b in ZIP code 19090.
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00014793; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Willow Grove?
In a normal year in Willow Grove, 22 days a year reach 90°F (1 of them 100°F or more) and 92 nights fall to 32°F or colder.
- Days at 90°F or more
- 22a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 92a normal year
- Days that stay below freezing
- 16high of 32°F or less
The highest temperature in this station's record (since 1945) is 104°F, on August 9, 2001; the lowest is −9°F, on January 17, 1982.
The wettest calendar year on that record is 1979, with 66.97 in; the snowiest season is 1995–96, with 68.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014793; records: ACIS (NOAA Regional Climate Centers), station USW00014793. Records use complete months only; a month missing more than three days is left out.
How sunny is Willow Grove?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Willow Grove, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 1.9 |
| February | 68% | 2.7 |
| March | 67% | 3.6 |
| April | 70% | 4.8 |
| May | 69% | 5.3 |
| June | 74% | 5.9 |
| July | 79% | 6.0 |
| August | 77% | 5.2 |
| September | 75% | 4.2 |
| October | 69% | 3.0 |
| November | 70% | 2.1 |
| December | 63% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Willow Grove need?
A normal year in Willow Grove brings 5,008 heating degree days, 7% fewer than the median U.S. place (5,373), and 1,027 cooling degree days, 13% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,507 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,024 | 0 |
| February | 851 | 0 |
| March | 721 | 0 |
| April | 392 | 14 |
| May | 149 | 62 |
| June | 22 | 204 |
| July | 1 | 340 |
| August | 3 | 279 |
| September | 61 | 114 |
| October | 309 | 14 |
| November | 594 | 0 |
| December | 882 | 0 |
| Year (annual) | 5,008 | 1,027 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014793. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Willow Grove's climate compare?
Willow Grove is warmer than 100 of the other 107 places with their own NOAA record in Pennsylvania. Across the 7,247 U.S. stations with normals, its annual mean of 54.0°F is warmer than 57%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Willow Grove share this climate record?
11 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Lansdale, PA19,154 people · 8 mi NW
- Horsham, PA15,866 people · 1 mi SE
- Montgomeryville, PA13,572 people · 6 mi NW
- Hatboro, PA8,341 people · 3 mi SE
- Ambler, PA6,900 people · 5 mi SW
- Maple Glen, PA6,851 people · 2 mi SW
- Fort Washington, PA6,105 people · 5 mi SW
- Spring House, PA5,068 people · 4 mi SW
- Brittany Farms-The Highlands, PA4,127 people · 6 mi NW
- Warminster Heights, PA4,013 people · 4 mi E
- North Wales, PA3,450 people · 7 mi W
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Willow Grove's climate
What is the coldest month in Willow Grove?
January, with a normal high of 40°F and a normal low of 24°F. The warmest is July (85°F by day, 67°F at night).
Does it snow in Willow Grove?
Yes. NOAA publishes no 1991-2020 snowfall normal for Willow Grove's NOAA station; the nearest record that keeps one, Neshaminy Falls (11 miles away), records 20 inches of snow in a normal year.
What plant hardiness zone is Willow Grove in?
The USDA's 2023 map puts Willow Grove in zone 7b in ZIP code 19090.
How late can frost come in Willow Grove?
In half of years the last 32°F night comes after April 11; in one year in ten it comes after April 27. Waiting until April 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Pennsylvania climateThe statewide normals and every place in the state
- Doylestown, PA9 miles from this station, 53.4°F a year
- Philadelphia NE Airport, PA11 miles from this station, 56.4°F a year
- Neshaminy Falls, PA11 miles from this station, 52.9°F a year
- Norristown, PA12 miles from this station, 55.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made