Lebanon, Pennsylvania climate: Normal weather by month, frost dates and records
Lebanon's normal year runs from 22°F January nights to 84°F July afternoons, with 46.4 inches of precipitation and 24 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 29°C, 1,179 mm of precipitation a year.
- NOAA stationLebanon (2 mi W)
- Station IDUSC00364896
- Location40.33°N 76.47°W
- Elevation450 ft (137 m)
- Population26,456
On October 23, the normal high in Lebanon 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 Lebanon.
- Jan 37° 22°
- Feb 40° 23°
- Mar 49° 31°
- Apr 62° 40°
- May 72° 51°
- Jun 80° 60°
- Jul 84° 64°
- Aug 82° 63°
- Sep 76° 55°
- Oct 64° 44°
- Nov 52° 34°
- Dec 42° 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 Lebanon each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 22°F. The most precipitation falls in July (4.85 in), the least in February (2.55 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. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 37°F | 22°F | 29.5°F | 3.06 | 6.8 | 10 | <1 | 27 | 9 h 40 min |
| February | 40°F | 23°F | 31.9°F | 2.55 | 7.8 | 9 | <1 | 24 | 10 h 40 min |
| March | 49°F | 31°F | 40.1°F | 3.60 | 4.2 | 11 | <1 | 20 | 11 h 50 min |
| April | 62°F | 40°F | 51.1°F | 3.72 | 0.4 | 12 | <1 | 6 | 13 h 10 min |
| May | 72°F | 51°F | 61.2°F | 3.99 | 0.0 | 13 | <1 | <1 | 14 h 20 min |
| June | 80°F | 60°F | 69.9°F | 4.49 | 0.0 | 11 | 2 | <1 | 15 h |
| July | 84°F | 64°F | 74.3°F | 4.85 | 0.0 | 11 | 6 | <1 | 14 h 50 min |
| August | 82°F | 63°F | 72.5°F | 4.63 | 0.0 | 10 | 3 | <1 | 13 h 50 min |
| September | 76°F | 55°F | 65.5°F | 4.63 | 0.0 | 10 | 1 | <1 | 12 h 30 min |
| October | 64°F | 44°F | 54.0°F | 4.10 | 0.3 | 10 | <1 | 3 | 11 h 10 min |
| November | 52°F | 34°F | 43.2°F | 3.21 | 0.5 | 9 | <1 | 15 | 10 h |
| December | 42°F | 27°F | 34.3°F | 3.57 | 4.0 | 10 | <1 | 25 | 9 h 20 min |
| Year (annual) | 62°F | 43°F | 52.3°F | 46.40 | 24.0 | 125 | 13 | 120 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −6°C | −1.4°C | 78 mm | 17 cm |
| February | 5°C | −5°C | −0.1°C | 65 mm | 20 cm |
| March | 10°C | −1°C | 4.5°C | 91 mm | 11 cm |
| April | 17°C | 5°C | 10.6°C | 94 mm | 1 cm |
| May | 22°C | 10°C | 16.2°C | 101 mm | 0 cm |
| June | 27°C | 15°C | 21.1°C | 114 mm | 0 cm |
| July | 29°C | 18°C | 23.5°C | 123 mm | 0 cm |
| August | 28°C | 17°C | 22.5°C | 118 mm | 0 cm |
| September | 24°C | 13°C | 18.6°C | 118 mm | 0 cm |
| October | 18°C | 7°C | 12.2°C | 104 mm | 1 cm |
| November | 11°C | 1°C | 6.2°C | 82 mm | 1 cm |
| December | 5°C | −3°C | 1.3°C | 91 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00364896; 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 Lebanon?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. 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 USC00364896.
When is the last frost in Lebanon?
In Lebanon, the last spring frost (32°F) comes after April 20 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 25 in half of years and before October 10 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 201 year in 10 after May 7; 9 in 10 after April 5
- First autumn frost, half of years before
- October 251 year in 10 before October 10; 9 in 10 before November 6
NOAA puts the median frost-free season at 185 days, and the season without a hard freeze (28°F) at 212 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Lebanon in zone 7a in ZIP code 17046, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Lebanon's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (29 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 USC00364896; 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 Lebanon?
In a normal year in Lebanon, 13 days a year reach 90°F, 120 nights fall to 32°F or colder and 125 days bring measurable precipitation.
- Days at 90°F or more
- 13a 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
- 23high of 32°F or less
- Days with 0.01 inch of precipitation
- 125a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1965) is 103°F, on July 4, 1966; the lowest is −22°F, on January 22, 1985.
The wettest calendar year on that record is 2018, with 79.52 in; the snowiest season is 1995–96, with 61.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00364896; records: ACIS (NOAA Regional Climate Centers), station USC00364896. Records use complete months only; a month missing more than three days is left out.
How sunny is Lebanon?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Lebanon, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (60%).
| 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 Lebanon need?
A normal year in Lebanon brings 5,455 heating degree days, 2% more than the median U.S. place (5,373), and 856 cooling degree days, 6% 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 3,214 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,100 | 0 |
| February | 927 | 0 |
| March | 774 | 0 |
| April | 421 | 6 |
| May | 166 | 50 |
| June | 25 | 170 |
| July | 1 | 289 |
| August | 5 | 238 |
| September | 78 | 93 |
| October | 352 | 11 |
| November | 656 | 0 |
| December | 952 | 0 |
| Year (annual) | 5,455 | 856 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00364896. 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 Lebanon been warmer than normal lately?
2025 averaged 52.1°F, 0.2°F below the 1991-2020 normal of 52.3°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.8°F | +1.5°F | 47.08 | 26.3 |
| 2022 | 52.8°F | +0.5°F | 43.12 | 15.3 |
| 2023 | 54.1°F | +1.8°F | 40.24 | 3.8 |
| 2024 | 54.1°F | +1.8°F | 42.62 | 24.2 |
| 2025 | 52.1°F | −0.2°F | 42.08 | 23.0 |
Over 43 complete years from 1967 to 2025, the station's annual mean temperature rose at a fitted 5.1°F per century (+0.28°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00364896; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Lebanon's climate compare?
Lebanon is warmer than 81 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 71. Across the 7,247 U.S. stations with normals, its annual mean of 52.3°F is warmer than 51%.
In the Köppen classification computed from these normals, Lebanon 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 Lebanon share this climate record?
26 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.
- Palmyra, PA7,735 people · 7 mi W
- Campbelltown, PA5,759 people · 7 mi SW
- Annville, PA4,859 people · 2 mi W
- Cornwall, PA4,660 people · 6 mi SE
- Myerstown, PA3,143 people · 9 mi E
- Pleasant Hill, PA3,072 people · 1 mi E
- Sand Hill, PA2,288 people · 3 mi NE
- Lebanon South, PA2,100 people · 3 mi E
- Pine Grove, PA2,071 people · 16 mi N
- Cleona, PA2,040 people · 1 mi NW
- Jonestown, PA1,654 people · 6 mi N
- Avon, PA1,532 people · 5 mi E
- Richland, PA1,513 people · 11 mi E
- Palmdale, PA1,507 people · 9 mi W
- West Myerstown, PA1,493 people · 8 mi E
- Fredericksburg, PA1,478 people · 8 mi N
- Hebron, PA1,038 people · 4 mi E
- Schaefferstown, PA938 people · 9 mi E
- Quentin, PA679 people · 4 mi SE
- Ravine, PA647 people · 17 mi N
- Bethel, PA534 people · 14 mi NE
- Mount Aetna, PA509 people · 11 mi NE
- Timber Hills, PA295 people · 6 mi S
- Mount Gretna Heights, PA246 people · 6 mi S
- Mount Gretna, PA191 people · 6 mi S
- Frystown, PA62 people · 11 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 Lebanon's climate
What is the coldest month in Lebanon?
January, with a normal high of 37°F and a normal low of 22°F. The warmest is July (84°F by day, 64°F at night).
Does it snow in Lebanon?
Yes: 24 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in February (7.8 inches).
What is the rainiest month in Lebanon?
July, with 4.85 in of precipitation in a normal year; the driest is February with 2.55 in.
What plant hardiness zone is Lebanon in?
The USDA's 2023 map puts Lebanon in zone 7a in ZIP code 17046, the nearest ZIP area. By the same method at Lebanon's NOAA station, the coldest night of a typical year reaches 1°F (29 years, 1991-2020): zone 7a.
How late can frost come in Lebanon?
In half of years the last 32°F night comes after April 20; in one year in ten it comes after May 7. Waiting until May 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Lebanon in OctoberThis month day by day, its records and recent years
- Pennsylvania climateThe statewide normals and every place in the state
- Landisville, PA15 miles from this station, 51.1°F a year
- Dehart Dam, PA17 miles from this station, 50.6°F a year
- Lancaster, PA17 miles from this station, 53.3°F a year
- Middletown, PA19 miles from this station, 54.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made