Donora, Pennsylvania climate: Normal weather by month, frost dates and records
Donora's normal year runs from 21°F January nights to 84°F July afternoons, with 40.9 inches of precipitation and 21 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.2°C, January lows of −6°C, July highs of 29°C, 1,038 mm of precipitation a year.
- NOAA stationDonora (1 mi SW)
- Station IDUSC00362190
- Location40.16°N 79.87°W
- Elevation762 ft (232 m)
- From the center1 miles
- Population4,482
On October 23, the normal high in Donora is 63°F and the normal low 40°F, and the chance of measurable rain or snow is 37%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Donora.
- Jan 39° 21°
- Feb 42° 22°
- Mar 51° 29°
- Apr 64° 38°
- May 73° 49°
- Jun 81° 58°
- Jul 84° 62°
- Aug 84° 61°
- Sep 78° 54°
- Oct 66° 42°
- Nov 54° 33°
- Dec 43° 26°
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 Donora each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 21°F. The most precipitation falls in June (4.39 in), the least in February (2.43 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 39°F | 21°F | 29.6°F | 2.90 | 5.7 | 15 | <1 | 26 | 9 h 40 min |
| February | 42°F | 22°F | 31.9°F | 2.43 | 7.2 | 12 | <1 | 23 | 10 h 40 min |
| March | 51°F | 29°F | 39.7°F | 3.14 | 4.6 | 13 | <1 | 19 | 11 h 50 min |
| April | 64°F | 38°F | 51.2°F | 3.40 | 0.1 | 14 | <1 | 7 | 13 h 10 min |
| May | 73°F | 49°F | 61.1°F | 4.30 | 0.0 | 14 | 1 | <1 | 14 h 20 min |
| June | 81°F | 58°F | 69.4°F | 4.39 | 0.0 | 13 | 3 | <1 | 15 h |
| July | 84°F | 62°F | 73.3°F | 4.31 | 0.0 | 11 | 5 | <1 | 14 h 50 min |
| August | 84°F | 61°F | 72.1°F | 3.64 | 0.0 | 10 | 5 | <1 | 13 h 50 min |
| September | 78°F | 54°F | 65.7°F | 3.55 | 0.0 | 10 | 2 | <1 | 12 h 30 min |
| October | 66°F | 42°F | 54.1°F | 3.05 | 0.0 | 12 | <1 | 3 | 11 h 10 min |
| November | 54°F | 33°F | 43.1°F | 2.84 | 0.5 | 12 | <1 | 15 | 10 h |
| December | 43°F | 26°F | 34.4°F | 2.90 | 3.3 | 13 | <1 | 24 | 9 h 20 min |
| Year (annual) | 63°F | 41°F | 52.1°F | 40.85 | 21.4 | 147 | 15 | 116 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −6°C | −1.3°C | 74 mm | 14 cm |
| February | 6°C | −6°C | −0.1°C | 62 mm | 18 cm |
| March | 11°C | −2°C | 4.3°C | 80 mm | 12 cm |
| April | 18°C | 4°C | 10.7°C | 86 mm | 0 cm |
| May | 23°C | 9°C | 16.2°C | 109 mm | 0 cm |
| June | 27°C | 15°C | 20.8°C | 112 mm | 0 cm |
| July | 29°C | 17°C | 22.9°C | 109 mm | 0 cm |
| August | 29°C | 16°C | 22.3°C | 92 mm | 0 cm |
| September | 25°C | 12°C | 18.7°C | 90 mm | 0 cm |
| October | 19°C | 6°C | 12.3°C | 77 mm | 0 cm |
| November | 12°C | 0°C | 6.2°C | 72 mm | 1 cm |
| December | 6°C | −4°C | 1.3°C | 74 mm | 8 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00362190; 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 Donora?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. Of those, September 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 USC00362190.
When is the last frost in Donora?
In Donora, the last spring frost (32°F) comes after April 27 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 8 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 271 year in 10 after May 15; 9 in 10 after April 11
- First autumn frost, half of years before
- October 221 year in 10 before October 8; 9 in 10 before November 4
NOAA puts the median frost-free season at 177 days, and the season without a hard freeze (28°F) at 201 days.
A hard freeze (28°F) comes after April 14 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Donora in zone 6b in ZIP code 15033. By the map's own method, the average of each year's coldest night over 1991-2020, Donora's NOAA station is in zone 6b: the coldest night of a typical year reaches 0°F (25 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 USC00362190; 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 Donora?
In a normal year in Donora, 15 days a year reach 90°F, 116 nights fall to 32°F or colder and 147 days bring measurable precipitation.
- Days at 90°F or more
- 15a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 116a normal year
- Days that stay below freezing
- 24high of 32°F or less
- Days with 0.01 inch of precipitation
- 147a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1926) is 105°F, on July 20, 1930; the lowest is −17°F, on January 22, 1985.
The wettest calendar year on that record is 2011, with 52.80 in; the snowiest season is 1960–61, with 60.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00362190; records: ACIS (NOAA Regional Climate Centers), station USC00362190. Records use complete months only; a month missing more than three days is left out.
How sunny is Donora?
Over a year 68% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Donora, 3.7 kWh per square metre a day. August is the sunniest month (76%) and December the cloudiest (51%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 53% | 1.6 |
| February | 58% | 2.4 |
| March | 61% | 3.4 |
| April | 66% | 4.6 |
| May | 69% | 5.3 |
| June | 73% | 5.9 |
| July | 76% | 5.9 |
| August | 76% | 5.3 |
| September | 75% | 4.3 |
| October | 66% | 2.9 |
| November | 65% | 2.0 |
| December | 51% | 1.3 |
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 Donora need?
A normal year in Donora brings 5,465 heating degree days, 2% more than the median U.S. place (5,373), and 812 cooling degree days, 11% 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 3,212 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,097 | 0 |
| February | 925 | 0 |
| March | 783 | 0 |
| April | 420 | 6 |
| May | 175 | 53 |
| June | 29 | 161 |
| July | 2 | 260 |
| August | 5 | 225 |
| September | 73 | 94 |
| October | 350 | 12 |
| November | 657 | 0 |
| December | 947 | 0 |
| Year (annual) | 5,465 | 812 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00362190. 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.
Has Donora been warmer than normal lately?
Over 63 complete years from 1928 to 2016, the station's annual mean temperature rose at a fitted 1.2°F per century (+0.07°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 Donora's climate compare?
Donora is warmer than 78 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 10. Across the 7,247 U.S. stations with normals, its annual mean of 52.1°F is warmer than 50%.
In the Köppen classification computed from these normals, Donora 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 Donora share this climate record?
14 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.
- West Newton, PA2,598 people · 6 mi NE
- Lynnwood-Pricedale, PA2,316 people · 2 mi S
- Perryopolis, PA1,621 people · 8 mi SE
- Collinsburg, PA1,278 people · 6 mi NE
- Fairhope, PA1,113 people · 4 mi SE
- Fellsburg, PA864 people · 3 mi NE
- Sutersville, PA549 people · 6 mi NE
- Star Junction, PA425 people · 9 mi SE
- Arnold City, PA344 people · 4 mi SE
- Smithton, PA336 people · 7 mi E
- Wyano, PA320 people · 10 mi E
- Elrama, PA268 people · 7 mi NW
- Bunola, PA167 people · 6 mi NW
- Webster, PA48 people · 2 mi NE
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 Donora's climate
What is the coldest month in Donora?
January, with a normal high of 39°F and a normal low of 21°F. The warmest is July (84°F by day, 62°F at night).
Does it snow in Donora?
Yes: 21 inches in a normal year, falling on 14 days with 0.1 inch or more, the most in February (7.2 inches).
What is the rainiest month in Donora?
June, with 4.39 in of precipitation in a normal year; the driest is February with 2.43 in.
What plant hardiness zone is Donora in?
The USDA's 2023 map puts Donora in zone 6b in ZIP code 15033. By the same method at Donora's NOAA station, the coldest night of a typical year reaches 0°F (25 years, 1991-2020): zone 6b.
How late can frost come in Donora?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 15. Waiting until May 15 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Pennsylvania climateThe statewide normals and every place in the state
- Charleroi, PA2 miles from this station, 52.9°F a year
- McKeesport, PA12 miles from this station, 51.7°F a year
- West Mifflin, PA14 miles from this station, 52.4°F a year
- Braddock, PA16 miles from this station, 52.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made