Graterford (1 mi E), Pennsylvania climate: Climate normals at a NOAA weather station
Graterford (1 mi E)'s normal year runs from 20°F January nights to 86°F July afternoons, with 48.5 inches of precipitation and 13 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.3°C, January lows of −6°C, July highs of 30°C, 1,232 mm of precipitation a year.
- NOAA stationGraterford (1 mi E)
- Station IDUSC00363437
- Location40.23°N 75.42°W
- Elevation279 ft (85 m)
On October 23, the normal high in Graterford (1 mi E) is 64°F and the normal low 39°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Graterford (1 mi E).
- Jan 40° 20°
- Feb 42° 22°
- Mar 50° 29°
- Apr 62° 39°
- May 72° 49°
- Jun 81° 59°
- Jul 86° 64°
- Aug 84° 61°
- Sep 78° 53°
- Oct 66° 41°
- Nov 55° 32°
- Dec 45° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Graterford (1 mi E) each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 20°F. The most precipitation falls in July (4.97 in), the least in February (2.63 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 20°F | 30.0°F | 3.32 | 3.9 | 8 | <1 | 28 | 9 h 40 min |
| February | 42°F | 22°F | 32.1°F | 2.63 | 5.4 | 6 | <1 | 24 | 10 h 40 min |
| March | 50°F | 29°F | 39.5°F | 3.89 | 1.3 | 9 | <1 | 22 | 11 h 50 min |
| April | 62°F | 39°F | 50.5°F | 3.80 | 0.1 | 10 | <1 | 8 | 13 h 10 min |
| May | 72°F | 49°F | 60.7°F | 3.99 | 0.0 | 10 | 1 | 1 | 14 h 20 min |
| June | 81°F | 59°F | 70.1°F | 4.21 | 0.0 | 9 | 4 | <1 | 15 h |
| July | 86°F | 64°F | 75.0°F | 4.97 | 0.0 | 10 | 9 | <1 | 14 h 50 min |
| August | 84°F | 61°F | 72.8°F | 4.56 | 0.0 | 9 | 6 | <1 | 13 h 50 min |
| September | 78°F | 53°F | 65.4°F | 4.90 | 0.0 | 8 | 2 | <1 | 12 h 30 min |
| October | 66°F | 41°F | 53.7°F | 4.52 | 0.0 | 9 | <1 | 8 | 11 h 10 min |
| November | 55°F | 32°F | 43.7°F | 3.35 | 0.0 | 8 | <1 | 18 | 10 h |
| December | 45°F | 25°F | 35.0°F | 4.38 | 2.2 | 9 | <1 | 26 | 9 h 20 min |
| Year (annual) | 64°F | 41°F | 52.4°F | 48.52 | 12.9 | 104 | 21 | 137 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −1.1°C | 84 mm | 10 cm |
| February | 6°C | −6°C | 0.1°C | 67 mm | 14 cm |
| March | 10°C | −2°C | 4.2°C | 99 mm | 3 cm |
| April | 17°C | 4°C | 10.3°C | 97 mm | 0 cm |
| May | 22°C | 10°C | 15.9°C | 101 mm | 0 cm |
| June | 27°C | 15°C | 21.2°C | 107 mm | 0 cm |
| July | 30°C | 18°C | 23.9°C | 126 mm | 0 cm |
| August | 29°C | 16°C | 22.7°C | 116 mm | 0 cm |
| September | 26°C | 11°C | 18.6°C | 124 mm | 0 cm |
| October | 19°C | 5°C | 12.1°C | 115 mm | 0 cm |
| November | 13°C | 0°C | 6.5°C | 85 mm | 0 cm |
| December | 7°C | −4°C | 1.7°C | 111 mm | 6 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00363437; 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.
Which months are mildest at Graterford (1 mi E)?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. Of those, September has the fewest days with rain (8).
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 USC00363437.
When is the last frost at Graterford (1 mi E)?
In Graterford (1 mi E), the last spring frost (32°F) comes after April 24 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 15 in half of years and before October 1 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 241 year in 10 after May 9; 9 in 10 after April 10
- First autumn frost, half of years before
- October 151 year in 10 before October 1; 9 in 10 before November 1
NOAA puts the median frost-free season at 173 days, and the season without a hard freeze (28°F) at 198 days.
A hard freeze (28°F) comes after April 10 in half of springs and before October 27 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Graterford (1 mi E) in zone 7a in ZIP code 19474, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6b: the coldest night of a typical year reaches −1°F (23 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00363437; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 at Graterford (1 mi E)?
In a normal year in Graterford (1 mi E), 21 days a year reach 90°F, 137 nights fall to 32°F or colder and 104 days bring measurable precipitation.
- Days at 90°F or more
- 21a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 137a normal year
- Days that stay below freezing
- 17high of 32°F or less
- Days with 0.01 inch of precipitation
- 104a normal year
- Days with 1 inch of snow or more
- 3a normal year
The highest temperature in this station's record (since 1960) is 106°F, on July 18, 1999; the lowest is −17°F, on January 20, 1994.
The wettest calendar year on that record is 2006, with 55.97 in; the snowiest season is 1965–66, with 37.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00363437; records: ACIS (NOAA Regional Climate Centers), station USC00363437. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Graterford (1 mi E)?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds at Graterford (1 mi E), 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 many heating and cooling degree days does Graterford (1 mi E) record?
A normal year at Graterford (1 mi E) brings 5,475 heating degree days, 2% more than the median U.S. place (5,373), and 906 cooling degree days, 0% fewer 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 3,234 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,085 | 0 |
| February | 921 | 0 |
| March | 791 | 0 |
| April | 443 | 7 |
| May | 182 | 49 |
| June | 29 | 183 |
| July | 2 | 310 |
| August | 7 | 248 |
| September | 86 | 96 |
| October | 362 | 13 |
| November | 639 | 0 |
| December | 930 | 0 |
| Year (annual) | 5,475 | 906 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00363437. 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.
Have recent years at Graterford (1 mi E) been warmer than normal?
Over 30 complete years from 1961 to 2018, the station's annual mean temperature rose at a fitted 4.4°F per century (+0.25°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Graterford (1 mi E)'s climate compare?
Graterford (1 mi E) is warmer than 83 of the 108 places with their own NOAA record in Pennsylvania, and wetter than 90. Across the 7,247 U.S. stations with normals, its annual mean of 52.4°F is warmer than 51%.
In the Köppen classification computed from these normals, Graterford (1 mi E) is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Graterford (1 mi E) 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.
- Harleysville, PA9,034 people · 4 mi NE
- Kulpsville, PA8,990 people · 5 mi E
- Collegeville, PA5,308 people · 3 mi SW
- Eagleville, PA4,880 people · 5 mi S
- Trappe, PA4,077 people · 3 mi SW
- Skippack, PA4,006 people · 1 mi SE
- Evansburg, PA2,692 people · 3 mi S
- Spring Mount, PA2,292 people · 4 mi NW
- Woxall, PA1,417 people · 6 mi N
- Schwenksville, PA1,297 people · 3 mi NW
- Green Lane, PA487 people · 8 mi N
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 Graterford (1 mi E)'s climate
What is the coldest month at Graterford (1 mi E)?
January, with a normal high of 40°F and a normal low of 20°F. The warmest is July (86°F by day, 64°F at night).
Does it snow at Graterford (1 mi E)?
Yes: 13 inches in a normal year, falling on 5 days with 0.1 inch or more, the most in February (5.4 inches).
What is the rainiest month at Graterford (1 mi E)?
July, with 4.97 in of precipitation in a normal year; the driest is February with 2.63 in.
What plant hardiness zone is Graterford (1 mi E) in?
The USDA's 2023 map puts Graterford (1 mi E) in zone 7a in ZIP code 19474, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −1°F (23 years, 1991-2020): zone 6b.
How late can frost come at Graterford (1 mi E)?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 9. Waiting until May 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Pennsylvania climateThe statewide normals and every place in the state
- Pottstown, PA7 miles from this station, 51.9°F a year
- Phoenixville, PA8 miles from this station, 54.4°F a year
- Norristown, PA9 miles from this station, 55.0°F a year
- Sellersville, PA11 miles from this station, 51.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made