West Chester weather in September: West Chester, Pennsylvania: normal highs, lows, rain and records for September
West Chester in September has a normal high of 78°F and a normal low of 54°F, a daily mean of 66°F, falling from 83°F on the 1st to 72°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 5.65 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 12°C, 144 mm of precipitation in September.
- NOAA stationWest Chester (2 mi NW)
- Station IDUSC00369464
- Location39.97°N 75.64°W
- Elevation375 ft (114 m)
- From the center2 miles
- Population22,758
- Jan 40° 20°
- Feb 43° 21°
- Mar 51° 29°
- Apr 63° 38°
- May 73° 49°
- Jun 82° 59°
- Jul 86° 64°
- Aug 84° 62°
- Sep 78° 54°
- Oct 66° 41°
- Nov 55° 32°
- Dec 44° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is West Chester in September?
The normal high is 78°F and the normal low 54°F, for a daily mean of 65.9°F. September is 7.1°F cooler than August and 12.2°F warmer than October. September is the 4th warmest month of the year in West Chester and the 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 2.2°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°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 34%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 83°F | 59°F | 30% | 19% |
| September 8 | 81°F | 57°F | 30% | 19% |
| September 15 | 79°F | 54°F | 31% | 20% |
| September 22 | 76°F | 51°F | 32% | 20% |
| September 30 | 72°F | 48°F | 34% | 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 | 83°F | 59°F | 30% | 19% | 13 h 10 min |
| September 2 | 83°F | 58°F | 30% | 19% | 13 h |
| September 3 | 82°F | 58°F | 30% | 19% | 13 h |
| September 4 | 82°F | 58°F | 30% | 19% | 13 h |
| September 5 | 82°F | 57°F | 30% | 19% | 13 h |
| September 6 | 82°F | 57°F | 30% | 19% | 12 h 50 min |
| September 7 | 81°F | 57°F | 30% | 19% | 12 h 50 min |
| September 8 | 81°F | 57°F | 30% | 19% | 12 h 50 min |
| September 9 | 81°F | 56°F | 30% | 19% | 12 h 50 min |
| September 10 | 80°F | 56°F | 30% | 19% | 12 h 40 min |
| September 11 | 80°F | 56°F | 30% | 20% | 12 h 40 min |
| September 12 | 80°F | 55°F | 30% | 20% | 12 h 40 min |
| September 13 | 79°F | 55°F | 30% | 20% | 12 h 40 min |
| September 14 | 79°F | 55°F | 31% | 20% | 12 h 30 min |
| September 15 | 79°F | 54°F | 31% | 20% | 12 h 30 min |
| September 16 | 78°F | 54°F | 31% | 20% | 12 h 30 min |
| September 17 | 78°F | 53°F | 31% | 20% | 12 h 30 min |
| September 18 | 77°F | 53°F | 31% | 20% | 12 h 20 min |
| September 19 | 77°F | 53°F | 31% | 20% | 12 h 20 min |
| September 20 | 77°F | 52°F | 32% | 20% | 12 h 20 min |
| September 21 | 76°F | 52°F | 32% | 20% | 12 h 20 min |
| September 22 | 76°F | 51°F | 32% | 20% | 12 h 10 min |
| September 23 | 75°F | 51°F | 32% | 21% | 12 h 10 min |
| September 24 | 75°F | 51°F | 32% | 21% | 12 h 10 min |
| September 25 | 74°F | 50°F | 33% | 21% | 12 h 10 min |
| September 26 | 74°F | 50°F | 33% | 21% | 12 h |
| September 27 | 74°F | 49°F | 33% | 21% | 12 h |
| September 28 | 73°F | 49°F | 33% | 21% | 12 h |
| September 29 | 73°F | 49°F | 34% | 21% | 11 h 50 min |
| September 30 | 72°F | 48°F | 34% | 22% | 11 h 50 min |
- Normal high
- 78°FSeptember average
- Normal low
- 54°FSeptember average
- Precipitation
- 5.65 inmonth total
- Days with precipitation
- 90.01 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
- 27
- Days at 80°F or more
- 14
- Sunshine
- 77%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00369464; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in West Chester in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 30 (34%). In all, 5.65 in falls on 9 days of a normal September, 2 of them with an inch or more.
In a normal September in West Chester, 2 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00369464.
What are the records for September in West Chester?
The warmest September temperature on this station's record (since 1893) is 101°F, on September 3, 1953; the coldest is 31°F, on September 26, 1983. The wettest September brought 14.81 in (1971).
Source: records: ACIS, station USC00369464. Records and recent months use complete months only.
How does September in West Chester 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; West Chester's is 78°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- West Chester in August84°F by day, 62°F at night
- West Chester in October66°F by day, 41°F at night
- West Chester 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