Coatesville, Pennsylvania climate: Normal weather by month, frost dates and records
Coatesville's normal year runs from 22°F January nights to 85°F July afternoons, with 52.1 inches of precipitation and 32 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.6°C, January lows of −6°C, July highs of 30°C, 1,324 mm of precipitation a year.
- NOAA stationCoatesville (2 mi W)
- Station IDUSC00361591
- Location39.98°N 75.86°W
- Elevation640 ft (195 m)
- From the center2 miles
- Population13,390
On October 24, the normal high in Coatesville is 62°F and the normal low 41°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Coatesville.
- Jan 39° 22°
- Feb 42° 23°
- Mar 50° 31°
- Apr 63° 40°
- May 73° 50°
- Jun 81° 59°
- Jul 85° 65°
- Aug 83° 63°
- Sep 77° 56°
- Oct 65° 44°
- Nov 54° 34°
- Dec 43° 27°
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 Coatesville each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 22°F. The most precipitation falls in September (5.17 in), the least in February (3.34 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 39°F | 22°F | 30.2°F | 4.05 | 7.9 | 12 | <1 | 27 | 9 h 40 min |
| February | 42°F | 23°F | 32.4°F | 3.34 | 11.5 | 10 | <1 | 24 | 10 h 40 min |
| March | 50°F | 31°F | 40.4°F | 4.80 | 6.3 | 12 | <1 | 20 | 11 h 50 min |
| April | 63°F | 40°F | 51.4°F | 4.10 | 1.1 | 12 | <1 | 6 | 13 h 10 min |
| May | 73°F | 50°F | 61.5°F | 4.02 | 0.0 | 11 | 1 | <1 | 14 h 20 min |
| June | 81°F | 59°F | 69.9°F | 4.54 | 0.0 | 11 | 3 | <1 | 15 h |
| July | 85°F | 65°F | 75.0°F | 4.55 | 0.0 | 11 | 7 | <1 | 14 h 50 min |
| August | 83°F | 63°F | 73.1°F | 4.58 | 0.0 | 10 | 5 | <1 | 13 h 50 min |
| September | 77°F | 56°F | 66.1°F | 5.17 | 0.0 | 10 | <1 | <1 | 12 h 30 min |
| October | 65°F | 44°F | 54.3°F | 4.57 | 0.0 | 9 | <1 | 4 | 11 h 10 min |
| November | 54°F | 34°F | 43.8°F | 3.61 | 0.7 | 10 | <1 | 14 | 10 h |
| December | 43°F | 27°F | 35.0°F | 4.79 | 4.4 | 11 | <1 | 25 | 9 h 20 min |
| Year (annual) | 63°F | 43°F | 52.8°F | 52.12 | 31.9 | 131 | 16 | 120 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −1.0°C | 103 mm | 20 cm |
| February | 5°C | −5°C | 0.2°C | 85 mm | 29 cm |
| March | 10°C | −1°C | 4.7°C | 122 mm | 16 cm |
| April | 17°C | 5°C | 10.8°C | 104 mm | 3 cm |
| May | 23°C | 10°C | 16.4°C | 102 mm | 0 cm |
| June | 27°C | 15°C | 21.1°C | 115 mm | 0 cm |
| July | 30°C | 18°C | 23.9°C | 116 mm | 0 cm |
| August | 29°C | 17°C | 22.8°C | 116 mm | 0 cm |
| September | 25°C | 13°C | 18.9°C | 131 mm | 0 cm |
| October | 18°C | 6°C | 12.4°C | 116 mm | 0 cm |
| November | 12°C | 1°C | 6.6°C | 92 mm | 2 cm |
| December | 6°C | −3°C | 1.7°C | 122 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00361591; 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 Coatesville?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, August has the fewest days with rain (10).
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 USC00361591.
When is the last frost in Coatesville?
In Coatesville, the last spring frost (32°F) comes after April 19 in half of years and after May 4 in one year in ten; the first autumn frost comes before October 25 in half of years and before October 11 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 191 year in 10 after May 4; 9 in 10 after April 3
- First autumn frost, half of years before
- October 251 year in 10 before October 11; 9 in 10 before November 7
NOAA puts the median frost-free season at 190 days, and the season without a hard freeze (28°F) at 216 days.
A hard freeze (28°F) comes after April 3 in half of springs and before November 6 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Coatesville in zone 7a in ZIP code 19358, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Coatesville's NOAA station is in zone 7a: the coldest night of a typical year reaches 2°F (17 complete years).
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00361591; 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 in Coatesville?
In a normal year in Coatesville, 16 days a year reach 90°F, 120 nights fall to 32°F or colder and 131 days bring measurable precipitation.
- Days at 90°F or more
- 16a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 120a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 131a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1983) is 100°F, on July 16, 1988; the lowest is −14°F, on January 22, 1984.
The wettest calendar year on that record is 1996, with 75.12 in; the snowiest season is 1995–96, with 81.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00361591; records: ACIS (NOAA Regional Climate Centers), station USC00361591. Records use complete months only; a month missing more than three days is left out.
How sunny is Coatesville?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Coatesville, 4.1 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (68%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 2.0 |
| February | 71% | 2.9 |
| March | 69% | 3.8 |
| April | 73% | 5.0 |
| May | 72% | 5.6 |
| June | 78% | 6.2 |
| July | 82% | 6.2 |
| August | 80% | 5.4 |
| September | 77% | 4.4 |
| October | 73% | 3.2 |
| November | 74% | 2.3 |
| December | 68% | 1.8 |
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 Coatesville need?
A normal year in Coatesville brings 5,338 heating degree days, 1% fewer than the median U.S. place (5,373), and 909 cooling degree days, 0% 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 3,302 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,079 | 0 |
| February | 914 | 0 |
| March | 763 | 0 |
| April | 415 | 7 |
| May | 160 | 53 |
| June | 26 | 173 |
| July | 1 | 310 |
| August | 4 | 255 |
| September | 67 | 100 |
| October | 344 | 10 |
| November | 636 | 0 |
| December | 930 | 0 |
| Year (annual) | 5,338 | 909 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00361591. 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 Coatesville's climate compare?
Coatesville is warmer than 91 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 101. Across the 7,247 U.S. stations with normals, its annual mean of 52.8°F is warmer than 53%.
In the Köppen classification computed from these normals, Coatesville 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 Coatesville share this climate record?
12 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.
- Thorndale, PA4,139 people · 6 mi E
- Parkesburg, PA3,984 people · 3 mi SW
- Hayti, PA2,464 people · 1 mi E
- Caln, PA2,074 people · 4 mi E
- South Coatesville, PA1,747 people · 3 mi E
- Westwood, PA1,432 people · 1 mi S
- Atglen, PA1,320 people · 7 mi SW
- Christiana, PA1,100 people · 8 mi W
- Pomeroy, PA902 people · 2 mi SW
- Sadsburyville, PA788 people · 2 mi W
- Modena, PA546 people · 3 mi SE
- Cochranville, PA429 people · 8 mi SW
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 Coatesville's climate
What is the coldest month in Coatesville?
January, with a normal high of 39°F and a normal low of 22°F. The warmest is July (85°F by day, 65°F at night).
Does it snow in Coatesville?
Yes: 32 inches in a normal year, falling on 20 days with 0.1 inch or more, the most in February (11.5 inches).
What is the rainiest month in Coatesville?
September, with 5.17 in of precipitation in a normal year; the driest is February with 3.34 in.
What plant hardiness zone is Coatesville in?
The USDA's 2023 map puts Coatesville in zone 7a in ZIP code 19358, the nearest ZIP area. By the same method at Coatesville's NOAA station, the coldest night of a typical year reaches 2°F (17 years, 1991-2020): zone 7a.
How late can frost come in Coatesville?
In half of years the last 32°F night comes after April 19; in one year in ten it comes after May 4. Waiting until May 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Pennsylvania climateThe statewide normals and every place in the state
- Avondale, PA9 miles from this station, 52.3°F a year
- Glenmoore, PA9 miles from this station, 52.5°F a year
- West Chester, PA12 miles from this station, 52.4°F a year
- Hopewell Morgantown, PA12 miles from this station, 52.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made