Harrisburg, Pennsylvania climate: Normal weather by month, frost dates and records
Harrisburg's normal year runs from 25°F January nights to 88°F July afternoons, with 41.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.9°C, January lows of −4°C, July highs of 31°C, 1,041 mm of precipitation a year.
- NOAA stationHarrisburg Capitol Cy Airport
- Station IDUSW00014751
- Location40.22°N 76.85°W
- Elevation340 ft (104 m)
- From the center4 miles
- Population50,649
On October 23, the normal high in Harrisburg is 64°F and the normal low 44°F, and the chance of measurable rain or snow is 33%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Harrisburg.
- Jan 40° 25°
- Feb 43° 26°
- Mar 53° 34°
- Apr 65° 43°
- May 75° 53°
- Jun 83° 63°
- Jul 88° 67°
- Aug 85° 66°
- Sep 79° 58°
- Oct 67° 47°
- Nov 55° 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 Harrisburg each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 25°F. The most precipitation falls in July (4.30 in), the least in February (2.36 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 25°F | 32.6°F | 2.64 | 9 | <1 | 26 | 9 h 40 min |
| February | 43°F | 26°F | 34.7°F | 2.36 | 9 | <1 | 23 | 10 h 40 min |
| March | 53°F | 34°F | 43.2°F | 3.35 | 11 | <1 | 16 | 11 h 50 min |
| April | 65°F | 43°F | 54.1°F | 3.70 | 12 | <1 | 3 | 13 h 10 min |
| May | 75°F | 53°F | 64.0°F | 3.48 | 14 | 2 | <1 | 14 h 20 min |
| June | 83°F | 63°F | 73.0°F | 3.72 | 12 | 5 | <1 | 15 h |
| July | 88°F | 67°F | 77.5°F | 4.30 | 12 | 10 | <1 | 14 h 50 min |
| August | 85°F | 66°F | 75.4°F | 3.68 | 11 | 7 | <1 | 13 h 50 min |
| September | 79°F | 58°F | 68.5°F | 4.12 | 10 | 2 | <1 | 12 h 30 min |
| October | 67°F | 47°F | 56.7°F | 3.68 | 11 | <1 | 1 | 11 h 10 min |
| November | 55°F | 37°F | 46.0°F | 2.80 | 9 | <1 | 10 | 10 h |
| December | 44°F | 30°F | 37.0°F | 3.15 | 10 | <1 | 22 | 9 h 20 min |
| Year (annual) | 65°F | 46°F | 55.2°F | 40.98 | 129 | 26 | 102 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −4°C | 0.3°C | 67 mm |
| February | 6°C | −3°C | 1.5°C | 60 mm |
| March | 11°C | 1°C | 6.2°C | 85 mm |
| April | 18°C | 6°C | 12.3°C | 94 mm |
| May | 24°C | 12°C | 17.8°C | 88 mm |
| June | 28°C | 17°C | 22.8°C | 94 mm |
| July | 31°C | 20°C | 25.3°C | 109 mm |
| August | 30°C | 19°C | 24.1°C | 93 mm |
| September | 26°C | 15°C | 20.3°C | 105 mm |
| October | 19°C | 8°C | 13.7°C | 93 mm |
| November | 13°C | 3°C | 7.8°C | 71 mm |
| December | 7°C | −1°C | 2.8°C | 80 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Harrisburg's own co-op station Harrisburg (1 mi NE) does: 24 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014751; 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 Harrisburg?
Normal highs sit between 65°F and 85°F in May, June, 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 USW00014751.
When is the last frost in Harrisburg?
In Harrisburg, the last spring frost (32°F) comes after April 9 in half of years and after April 25 in one year in ten; the first autumn frost comes before November 1 in half of years and before October 16 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 91 year in 10 after April 25; 9 in 10 after March 27
- First autumn frost, half of years before
- November 11 year in 10 before October 16; 9 in 10 before November 15
NOAA puts the median frost-free season at 205 days, and the season without a hard freeze (28°F) at 231 days.
A hard freeze (28°F) comes after March 29 in half of springs and before November 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Harrisburg in zone 7a across its 5 ZIP code areas (7a in 17110, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Harrisburg's NOAA station is in zone 7b: the coldest night of a typical year reaches 6°F (19 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 USW00014751; 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.
What hardiness zone is each Harrisburg ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Harrisburg's 5 ZIP code areas are all in zone 7a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Harrisburg?
In a normal year in Harrisburg, 26 days a year reach 90°F (1 of them 100°F or more), 102 nights fall to 32°F or colder and 129 days bring measurable precipitation.
- Days at 90°F or more
- 26a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 102a normal year
- Days that stay below freezing
- 17high of 32°F or less
- Days with 0.01 inch of precipitation
- 129a normal year
The highest temperature in this station's record (since 1939) is 107°F, on July 3, 1966; the lowest is −9°F, on January 22, 1984.
The wettest calendar year on that record is 2018, with 62.03 in; the snowiest season is 1960–61, with 81.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014751; records: ACIS (NOAA Regional Climate Centers), station USW00014751. Records use complete months only; a month missing more than three days is left out.
How sunny is Harrisburg?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Harrisburg, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (60%). Among the 459 U.S. places of 50,000 or more, that ranks tied 416th (with 11 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.8 |
| February | 66% | 2.7 |
| March | 66% | 3.6 |
| April | 69% | 4.8 |
| May | 69% | 5.3 |
| June | 75% | 6.0 |
| July | 79% | 6.0 |
| August | 76% | 5.2 |
| September | 74% | 4.2 |
| October | 68% | 2.9 |
| November | 69% | 2.1 |
| December | 60% | 1.5 |
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 Harrisburg need?
A normal year in Harrisburg brings 4,756 heating degree days, 11% fewer than the median U.S. place (5,373), and 1,230 cooling degree days, 36% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,840 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,004 | 0 |
| February | 848 | 0 |
| March | 675 | 1 |
| April | 341 | 14 |
| May | 116 | 83 |
| June | 10 | 250 |
| July | 0 | 387 |
| August | 1 | 325 |
| September | 43 | 148 |
| October | 279 | 22 |
| November | 569 | 0 |
| December | 870 | 0 |
| Year (annual) | 4,756 | 1,230 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014751. 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 Harrisburg been warmer than normal lately?
2024 averaged 57.9°F, 2.7°F above the 1991-2020 normal of 55.2°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 57.0°F | +1.8°F | 39.93 |
| 2022 | 56.1°F | +0.9°F | 37.89 |
| 2023 | 58.0°F | +2.8°F | 33.91 |
| 2024 | 57.9°F | +2.7°F | 36.94 |
Over 147 complete years from 1841 to 2025, the station's annual mean temperature rose at a fitted 0.5°F per century (+0.03°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00014751; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Harrisburg's climate compare?
Harrisburg is warmer than 105 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 13. Across the 7,247 U.S. stations with normals, its annual mean of 55.2°F is warmer than 61%.
In the Köppen classification computed from these normals, Harrisburg is Cfa: temperate, 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 Harrisburg share this climate record?
24 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.
- Colonial Park, PA18,125 people · 6 mi NE
- Progress, PA11,143 people · 5 mi N
- Mechanicsburg, PA10,085 people · 8 mi W
- Camp Hill, PA8,231 people · 4 mi NW
- New Cumberland, PA7,625 people · 2 mi NW
- Lower Allen, PA7,582 people · 3 mi W
- Steelton, PA6,358 people · 1 mi NE
- Enola, PA5,913 people · 7 mi NW
- Lawnton, PA4,871 people · 4 mi NE
- Lemoyne, PA4,824 people · 3 mi NW
- Paxtonia, PA4,530 people · 8 mi NE
- Penbrook, PA3,263 people · 4 mi N
- Wormleysburg, PA3,096 people · 4 mi NW
- Marysville, PA2,721 people · 9 mi NW
- Messiah College, PA2,273 people · 8 mi SW
- Bressler, PA2,129 people · 2 mi NE
- Shiremanstown, PA1,669 people · 6 mi W
- Paxtang, PA1,640 people · 3 mi N
- West Fairview, PA1,221 people · 6 mi NW
- Enhaut, PA1,140 people · 2 mi NE
- New Market, PA826 people · 0 mi NW
- Dauphin, PA796 people · 11 mi N
- Oberlin, PA452 people · 2 mi NE
- Lewisberry, PA384 people · 6 mi S
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Harrisburg's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Harrisburg. This page uses Harrisburg Capitol Cy Airport; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Harrisburg (1 mi NE) USC00363698 | 1 mi NE | 420 ft | 51.9°F | 22°F | 85°F | 45.2 | 24 | April 15 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Harrisburg's climate
What is the coldest month in Harrisburg?
January, with a normal high of 40°F and a normal low of 25°F. The warmest is July (88°F by day, 67°F at night).
Does it snow in Harrisburg?
Yes. NOAA publishes no 1991-2020 snowfall normal for Harrisburg's NOAA station; Harrisburg's own co-op station Harrisburg (1 mi NE) records 24 inches of snow in a normal year.
What is the rainiest month in Harrisburg?
July, with 4.30 in of precipitation in a normal year; the driest is February with 2.36 in.
What plant hardiness zone is Harrisburg in?
The USDA's 2023 map puts Harrisburg in zone 7a across its 5 ZIP code areas (7a in 17110, the largest). By the same method at Harrisburg's NOAA station, the coldest night of a typical year reaches 6°F (19 years, 1991-2020): zone 7b.
How late can frost come in Harrisburg?
In half of years the last 32°F night comes after April 9; in one year in ten it comes after April 25. Waiting until April 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Harrisburg in OctoberThis month day by day, its records and recent years
- Pennsylvania climateThe statewide normals and every place in the state
- Middletown, PA5 miles from this station, 54.3°F a year
- Dehart Dam, PA17 miles from this station, 50.6°F a year
- Carlisle, PA18 miles from this station, 51.9°F a year
- York, PA21 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