Lancaster weather in September: Lancaster, Pennsylvania: normal highs, lows, rain and records for September
Lancaster in September has a normal high of 78°F and a normal low of 56°F, a daily mean of 67°F, falling from 83°F on the 1st to 72°F by the 30th. Measurable precipitation falls on 11 days in a normal September, 4.69 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 25°C and low of 13°C, 119 mm of precipitation in September.
- NOAA stationLancaster Airport
- Station IDUSW00054737
- Location40.12°N 76.29°W
- Elevation403 ft (123 m)
- From the center5 miles
- Population58,441
- Jan 40° 22°
- Feb 42° 23°
- Mar 52° 31°
- Apr 64° 40°
- May 74° 50°
- Jun 82° 60°
- Jul 86° 65°
- Aug 85° 63°
- Sep 78° 56°
- Oct 66° 44°
- Nov 54° 34°
- Dec 44° 27°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Lancaster in September?
The normal high is 78°F and the normal low 56°F, for a daily mean of 66.6°F. September is 6.9°F cooler than August and 11.7°F warmer than October. September is the 4th warmest month of the year in Lancaster and the 2nd wettest. Across the month the normal high falls 11°F, from 83°F on September 1 to 72°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 65°F and 69°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 37%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 83°F | 60°F | 37% | 20% |
| September 8 | 81°F | 58°F | 36% | 19% |
| September 15 | 78°F | 56°F | 36% | 20% |
| September 22 | 76°F | 53°F | 36% | 20% |
| September 30 | 72°F | 50°F | 37% | 20% |
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 | 83°F | 60°F | 37% | 20% | 13 h 10 min |
| September 2 | 82°F | 60°F | 37% | 20% | 13 h |
| September 3 | 82°F | 59°F | 37% | 20% | 13 h |
| September 4 | 82°F | 59°F | 36% | 20% | 13 h |
| September 5 | 82°F | 59°F | 36% | 20% | 13 h |
| September 6 | 81°F | 59°F | 36% | 20% | 12 h 50 min |
| September 7 | 81°F | 58°F | 36% | 19% | 12 h 50 min |
| September 8 | 81°F | 58°F | 36% | 19% | 12 h 50 min |
| September 9 | 80°F | 58°F | 36% | 19% | 12 h 50 min |
| September 10 | 80°F | 58°F | 36% | 19% | 12 h 40 min |
| September 11 | 80°F | 57°F | 36% | 19% | 12 h 40 min |
| September 12 | 79°F | 57°F | 36% | 20% | 12 h 40 min |
| September 13 | 79°F | 57°F | 36% | 20% | 12 h 40 min |
| September 14 | 79°F | 56°F | 36% | 20% | 12 h 30 min |
| September 15 | 78°F | 56°F | 36% | 20% | 12 h 30 min |
| September 16 | 78°F | 56°F | 36% | 20% | 12 h 30 min |
| September 17 | 78°F | 55°F | 36% | 20% | 12 h 30 min |
| September 18 | 77°F | 55°F | 36% | 20% | 12 h 20 min |
| September 19 | 77°F | 55°F | 36% | 20% | 12 h 20 min |
| September 20 | 76°F | 54°F | 36% | 20% | 12 h 20 min |
| September 21 | 76°F | 54°F | 36% | 20% | 12 h 20 min |
| September 22 | 76°F | 53°F | 36% | 20% | 12 h 10 min |
| September 23 | 75°F | 53°F | 36% | 20% | 12 h 10 min |
| September 24 | 75°F | 53°F | 37% | 20% | 12 h 10 min |
| September 25 | 74°F | 52°F | 37% | 20% | 12 h 10 min |
| September 26 | 74°F | 52°F | 37% | 20% | 12 h |
| September 27 | 73°F | 51°F | 37% | 20% | 12 h |
| September 28 | 73°F | 51°F | 37% | 20% | 12 h |
| September 29 | 73°F | 51°F | 37% | 20% | 11 h 50 min |
| September 30 | 72°F | 50°F | 37% | 20% | 11 h 50 min |
- Normal high
- 78°FSeptember average
- Normal low
- 56°FSeptember average
- Precipitation
- 4.69 inmonth total
- Days with precipitation
- 110.01 inch or more
- Days at 90°F or more
- 2
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 25
- Days at 80°F or more
- 12
- Sunshine
- 74%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00054737; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lancaster in September?
On a given September day the chance of 0.01 inch or more is 36% on average, highest around September 1 (37%). In all, 4.69 in falls on 11 days of a normal September, 1 of them with an inch or more.
In a normal September in Lancaster, 2 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00054737.
What are the records for September in Lancaster?
The warmest September temperature on this station's record (since 1999) is 98°F, on September 7, 2023; the coldest is 37°F, on September 30, 2000. The wettest September brought 13.07 in (2011).
The September mean against the 1991-2020 normal of 66.6°F: 2021 68.8°F (+2.2), 2022 67.9°F (+1.3), 2023 69.1°F (+2.5), 2024 66.8°F (+0.2), 2025 68.5°F (+1.9), 2026 68.1°F (+1.5). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 68.8°F | +2.2°F | 9.58 in |
| 2022 | 67.9°F | +1.3°F | 4.24 in |
| 2023 | 69.1°F | +2.5°F | 5.83 in |
| 2024 | 66.8°F | +0.2°F | 2.05 in |
| 2025 | 68.5°F | +1.9°F | – |
| 2026 | 68.1°F | +1.5°F | 4.77 in |
Source: records: ACIS, station USW00054737; recent months: ACIS, station USW00054737. Records and recent months use complete months only.
How does September in Lancaster 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; Lancaster's is 78°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Lancaster in August85°F by day, 63°F at night
- Lancaster in October66°F by day, 44°F at night
- Lancaster 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