Lebanon weather in September: Lebanon, Pennsylvania: normal highs, lows, rain and records for September
Lebanon in September has a normal high of 76°F and a normal low of 55°F, a daily mean of 66°F, falling from 80°F on the 1st to 70°F by the 30th. Measurable precipitation falls on 10 days in a normal September, 4.63 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 24°C and low of 13°C, 118 mm of precipitation in September.
- NOAA stationLebanon (2 mi W)
- Station IDUSC00364896
- Location40.33°N 76.47°W
- Elevation450 ft (137 m)
- Population26,456
- 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.
How warm is Lebanon in September?
The normal high is 76°F and the normal low 55°F, for a daily mean of 65.5°F. September is 7.0°F cooler than August and 11.5°F warmer than October. September is the 4th warmest month of the year in Lebanon and the 2nd wettest. Across the month the normal high falls 10°F, from 80°F on September 1 to 70°F on September 30. From one year to the next September's mean temperature typically moves about 2.1°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 63°F and 68°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 33%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 80°F | 60°F | 30% | 20% |
| September 8 | 78°F | 58°F | 30% | 20% |
| September 15 | 76°F | 56°F | 31% | 21% |
| September 22 | 73°F | 53°F | 32% | 22% |
| September 30 | 70°F | 50°F | 33% | 22% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 80°F | 60°F | 30% | 20% | 13 h 10 min |
| September 2 | 80°F | 60°F | 30% | 20% | 13 h 10 min |
| September 3 | 80°F | 60°F | 30% | 20% | 13 h |
| September 4 | 79°F | 59°F | 30% | 20% | 13 h |
| September 5 | 79°F | 59°F | 30% | 20% | 13 h |
| September 6 | 79°F | 59°F | 30% | 20% | 12 h 50 min |
| September 7 | 79°F | 58°F | 30% | 20% | 12 h 50 min |
| September 8 | 78°F | 58°F | 30% | 20% | 12 h 50 min |
| September 9 | 78°F | 58°F | 30% | 20% | 12 h 50 min |
| September 10 | 78°F | 58°F | 30% | 20% | 12 h 40 min |
| September 11 | 77°F | 57°F | 30% | 20% | 12 h 40 min |
| September 12 | 77°F | 57°F | 30% | 20% | 12 h 40 min |
| September 13 | 77°F | 57°F | 31% | 20% | 12 h 40 min |
| September 14 | 76°F | 56°F | 31% | 20% | 12 h 30 min |
| September 15 | 76°F | 56°F | 31% | 21% | 12 h 30 min |
| September 16 | 76°F | 55°F | 31% | 21% | 12 h 30 min |
| September 17 | 75°F | 55°F | 31% | 21% | 12 h 30 min |
| September 18 | 75°F | 55°F | 31% | 21% | 12 h 20 min |
| September 19 | 75°F | 54°F | 31% | 21% | 12 h 20 min |
| September 20 | 74°F | 54°F | 31% | 21% | 12 h 20 min |
| September 21 | 74°F | 54°F | 32% | 21% | 12 h 20 min |
| September 22 | 73°F | 53°F | 32% | 22% | 12 h 10 min |
| September 23 | 73°F | 53°F | 32% | 22% | 12 h 10 min |
| September 24 | 73°F | 52°F | 32% | 22% | 12 h 10 min |
| September 25 | 72°F | 52°F | 32% | 22% | 12 h 10 min |
| September 26 | 72°F | 52°F | 33% | 22% | 12 h |
| September 27 | 71°F | 51°F | 33% | 22% | 12 h |
| September 28 | 71°F | 51°F | 33% | 22% | 12 h |
| September 29 | 71°F | 50°F | 33% | 22% | 11 h 50 min |
| September 30 | 70°F | 50°F | 33% | 22% | 11 h 50 min |
- Normal high
- 76°FSeptember average
- Normal low
- 55°FSeptember average
- Precipitation
- 4.63 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 24
- Days at 80°F or more
- 10
- Sunshine
- 74%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00364896; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lebanon in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 28 (33%). In all, 4.63 in falls on 10 days of a normal September, 1 of them with an inch or more.
In a normal September in Lebanon, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00364896.
What are the records for September in Lebanon?
The warmest September temperature on this station's record (since 1965) is 98°F, on September 11, 1983; the coldest is 33°F, on September 29, 2000. The wettest September brought 17.99 in (2011).
The September mean against the 1991-2020 normal of 65.5°F: 2021 66.9°F (+1.4), 2022 65.8°F (+0.3), 2023 66.3°F (+0.8), 2024 65.7°F (+0.2), 2025 67.7°F (+2.2). 5 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 66.9°F | +1.4°F | 11.50 in |
| 2022 | 65.8°F | +0.3°F | 3.63 in |
| 2023 | 66.3°F | +0.8°F | 4.28 in |
| 2024 | 65.7°F | +0.2°F | 2.19 in |
| 2025 | 67.7°F | +2.2°F | 1.55 in |
Source: records: ACIS, station USC00364896; recent months: ACIS, station USC00364896. Records and recent months use complete months only.
How does September in Lebanon compare across Pennsylvania?
Across the 108 places PlainClimate covers in Pennsylvania, September normal highs run from 68°F in Laporte to 80°F in Marcus Hook; Lebanon's is 76°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Lebanon in August82°F by day, 63°F at night
- Lebanon in October64°F by day, 44°F at night
- Lebanon through the yearEvery month, frost dates, records and recent years
- Pennsylvania in SeptemberThe statewide normal and the warmest and coolest places
- Marcus Hook: Pennsylvania's warmest Septembernormal high 80°F