Carlisle, Pennsylvania climate: Normal weather by month, frost dates and records
Carlisle's normal year runs from 21°F January nights to 86°F July afternoons, with 48.0 inches of precipitation and 28 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.1°C, January lows of −6°C, July highs of 30°C, 1,220 mm of precipitation a year.
- NOAA stationCarlisle Water Treatment Plant
- Station IDUSC00361920
- Location40.23°N 77.19°W
- Elevation430 ft (131 m)
- Population22,517
On October 14, the normal high in Carlisle is 67°F and the normal low 42°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Carlisle.
- Jan 38° 21°
- Feb 41° 22°
- Mar 50° 29°
- Apr 63° 39°
- May 73° 49°
- Jun 81° 59°
- Jul 86° 63°
- Aug 84° 61°
- Sep 77° 53°
- Oct 66° 42°
- Nov 54° 32°
- Dec 42° 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 in Carlisle each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 21°F. The most precipitation falls in July (5.45 in), the least in February (2.58 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 38°F | 21°F | 29.3°F | 3.06 | 7.7 | 9 | <1 | 28 | 9 h 40 min |
| February | 41°F | 22°F | 31.3°F | 2.58 | 9.6 | 9 | <1 | 25 | 10 h 40 min |
| March | 50°F | 29°F | 39.5°F | 4.05 | 4.8 | 9 | <1 | 21 | 11 h 50 min |
| April | 63°F | 39°F | 50.5°F | 3.79 | 0.2 | 11 | <1 | 7 | 13 h 10 min |
| May | 73°F | 49°F | 60.7°F | 4.73 | 0.0 | 15 | 1 | <1 | 14 h 20 min |
| June | 81°F | 59°F | 69.8°F | 4.42 | 0.0 | 12 | 4 | <1 | 15 h |
| July | 86°F | 63°F | 74.0°F | 5.45 | 0.0 | 11 | 10 | <1 | 14 h 50 min |
| August | 84°F | 61°F | 72.3°F | 4.03 | 0.0 | 11 | 5 | <1 | 13 h 50 min |
| September | 77°F | 53°F | 65.3°F | 4.96 | 0.0 | 9 | 3 | <1 | 12 h 30 min |
| October | 66°F | 42°F | 53.7°F | 4.26 | 0.5 | 11 | <1 | 4 | 11 h 10 min |
| November | 54°F | 32°F | 42.9°F | 3.13 | 0.9 | 8 | <1 | 17 | 10 h |
| December | 42°F | 25°F | 33.7°F | 3.57 | 4.0 | 10 | <1 | 25 | 9 h 20 min |
| Year (annual) | 63°F | 41°F | 51.9°F | 48.03 | 27.7 | 125 | 24 | 127 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −6°C | −1.5°C | 78 mm | 20 cm |
| February | 5°C | −6°C | −0.4°C | 66 mm | 24 cm |
| March | 10°C | −2°C | 4.2°C | 103 mm | 12 cm |
| April | 17°C | 4°C | 10.3°C | 96 mm | 1 cm |
| May | 23°C | 9°C | 15.9°C | 120 mm | 0 cm |
| June | 27°C | 15°C | 21.0°C | 112 mm | 0 cm |
| July | 30°C | 17°C | 23.3°C | 138 mm | 0 cm |
| August | 29°C | 16°C | 22.4°C | 102 mm | 0 cm |
| September | 25°C | 12°C | 18.5°C | 126 mm | 0 cm |
| October | 19°C | 5°C | 12.1°C | 108 mm | 1 cm |
| November | 12°C | 0°C | 6.1°C | 80 mm | 2 cm |
| December | 6°C | −4°C | 0.9°C | 91 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00361920; 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 Carlisle?
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 (9).
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 USC00361920.
When is the last frost in Carlisle?
In Carlisle, the last spring frost (32°F) comes after April 23 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 18 in half of years and before October 4 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 231 year in 10 after May 9; 9 in 10 after April 9
- First autumn frost, half of years before
- October 181 year in 10 before October 4; 9 in 10 before November 2
NOAA puts the median frost-free season at 177 days, and the season without a hard freeze (28°F) at 202 days.
A hard freeze (28°F) comes after April 10 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Carlisle in zone 7a in ZIP code 17013.
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00361920; 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 Carlisle?
In a normal year in Carlisle, 24 days a year reach 90°F, 127 nights fall to 32°F or colder and 125 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 127a normal year
- Days that stay below freezing
- 20high of 32°F or less
- Days with 0.01 inch of precipitation
- 125a normal year
- Days with 1 inch of snow or more
- 8a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00361920.
How sunny is Carlisle?
Over a year 70% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Carlisle, 3.8 kWh per square metre a day. July is the sunniest month (77%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 60% | 1.8 |
| February | 65% | 2.6 |
| March | 64% | 3.6 |
| April | 67% | 4.7 |
| May | 68% | 5.3 |
| June | 74% | 5.9 |
| July | 77% | 5.9 |
| August | 76% | 5.2 |
| September | 73% | 4.2 |
| October | 67% | 2.9 |
| November | 67% | 2.1 |
| December | 58% | 1.4 |
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 Carlisle need?
A normal year in Carlisle brings 5,559 heating degree days, 3% more than the median U.S. place (5,373), and 826 cooling degree days, 9% 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 3,156 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,107 | 0 |
| February | 944 | 0 |
| March | 792 | 0 |
| April | 439 | 5 |
| May | 174 | 40 |
| June | 23 | 167 |
| July | 1 | 280 |
| August | 4 | 230 |
| September | 83 | 92 |
| October | 362 | 12 |
| November | 663 | 0 |
| December | 969 | 0 |
| Year (annual) | 5,559 | 826 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00361920. 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 Carlisle been warmer than normal lately?
2025 averaged 52.0°F, 0.1°F above the 1991-2020 normal of 51.9°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 54.0°F | +2.1°F | 43.35 | 23.2 |
| 2022 | 52.3°F | +0.4°F | 40.86 | 18.9 |
| 2023 | 54.0°F | +2.1°F | 37.87 | 4.2 |
| 2024 | 54.2°F | +2.3°F | 47.65 | 26.1 |
| 2025 | 52.0°F | +0.1°F | 35.49 | 16.5 |
Source: observed years: ACIS, station USC00361920. A year counts only with all twelve months complete.
How does Carlisle's climate compare?
Carlisle is warmer than 73 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 85. Across the 7,247 U.S. stations with normals, its annual mean of 51.9°F is warmer than 49%.
In the Köppen classification computed from these normals, Carlisle 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 Carlisle 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.
- Schlusser, PA5,926 people · 1 mi N
- Boiling Springs, PA3,602 people · 5 mi SE
- Dillsburg, PA2,651 people · 11 mi SE
- Mount Holly Springs, PA2,024 people · 8 mi S
- Newport, PA1,522 people · 18 mi N
- Duncannon, PA1,471 people · 14 mi NE
- Bloomfield, PA1,258 people · 13 mi N
- Carlisle Barracks, PA683 people · 1 mi SE
- Franklintown, PA554 people · 13 mi SE
- New Kingstown, PA439 people · 6 mi E
- Plainfield, PA283 people · 5 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 Carlisle's climate
What is the coldest month in Carlisle?
January, with a normal high of 38°F and a normal low of 21°F. The warmest is July (86°F by day, 63°F at night).
Does it snow in Carlisle?
Yes: 28 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in February (9.6 inches).
What is the rainiest month in Carlisle?
July, with 5.45 in of precipitation in a normal year; the driest is February with 2.58 in.
What plant hardiness zone is Carlisle in?
The USDA's 2023 map puts Carlisle in zone 7a in ZIP code 17013.
How late can frost come in Carlisle?
In half of years the last 32°F night comes after April 23; 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
- Bloserville (1 mi N), PA9 miles from this station, 51.8°F a year
- Harrisburg, PA18 miles from this station, 55.2°F a year
- Biglerville, PA21 miles from this station, 52.8°F a year
- Shippensburg, PA21 miles from this station, 53.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made