Lewes weather in September: Lewes, Delaware: normal highs, lows, rain and records for September
Lewes in September has a normal high of 80°F and a normal low of 64°F, a daily mean of 72°F, falling from 84°F on the 1st to 75°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 4.49 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 18°C, 114 mm of precipitation in September.
- NOAA stationLewes
- Station IDUSC00075320
- Location38.78°N 75.16°W
- Elevation10 ft (3 m)
- Population3,702
- Jan 46° 30°
- Feb 48° 32°
- Mar 55° 38°
- Apr 66° 46°
- May 75° 56°
- Jun 83° 66°
- Jul 88° 71°
- Aug 86° 69°
- Sep 80° 64°
- Oct 69° 52°
- Nov 59° 42°
- Dec 50° 35°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Lewes in September?
The normal high is 80°F and the normal low 64°F, for a daily mean of 71.7°F. September is 5.6°F cooler than August and 10.8°F warmer than October. September is the 4th warmest month of the year in Lewes and the 2nd wettest. Across the month the normal high falls 9°F, from 84°F on September 1 to 75°F on September 30. From one year to the next September's mean temperature typically moves about 1.9°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 70°F and 74°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 31%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 84°F | 68°F | 27% | 18% |
| September 8 | 82°F | 66°F | 28% | 18% |
| September 15 | 80°F | 64°F | 29% | 19% |
| September 22 | 78°F | 62°F | 30% | 20% |
| September 30 | 75°F | 59°F | 31% | 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 | 84°F | 68°F | 27% | 18% | 13 h |
| September 2 | 83°F | 67°F | 27% | 18% | 13 h |
| September 3 | 83°F | 67°F | 28% | 18% | 13 h |
| September 4 | 83°F | 67°F | 28% | 18% | 13 h |
| September 5 | 83°F | 67°F | 28% | 18% | 12 h 50 min |
| September 6 | 83°F | 67°F | 28% | 18% | 12 h 50 min |
| September 7 | 82°F | 66°F | 28% | 18% | 12 h 50 min |
| September 8 | 82°F | 66°F | 28% | 18% | 12 h 50 min |
| September 9 | 82°F | 66°F | 28% | 18% | 12 h 40 min |
| September 10 | 82°F | 66°F | 28% | 19% | 12 h 40 min |
| September 11 | 81°F | 65°F | 28% | 19% | 12 h 40 min |
| September 12 | 81°F | 65°F | 28% | 19% | 12 h 40 min |
| September 13 | 81°F | 65°F | 28% | 19% | 12 h 40 min |
| September 14 | 80°F | 65°F | 28% | 19% | 12 h 30 min |
| September 15 | 80°F | 64°F | 29% | 19% | 12 h 30 min |
| September 16 | 80°F | 64°F | 29% | 19% | 12 h 30 min |
| September 17 | 79°F | 64°F | 29% | 19% | 12 h 30 min |
| September 18 | 79°F | 63°F | 29% | 19% | 12 h 20 min |
| September 19 | 79°F | 63°F | 29% | 19% | 12 h 20 min |
| September 20 | 78°F | 63°F | 30% | 20% | 12 h 20 min |
| September 21 | 78°F | 62°F | 30% | 20% | 12 h 20 min |
| September 22 | 78°F | 62°F | 30% | 20% | 12 h 10 min |
| September 23 | 77°F | 61°F | 30% | 20% | 12 h 10 min |
| September 24 | 77°F | 61°F | 30% | 20% | 12 h 10 min |
| September 25 | 77°F | 61°F | 31% | 20% | 12 h 10 min |
| September 26 | 76°F | 60°F | 31% | 20% | 12 h |
| September 27 | 76°F | 60°F | 31% | 20% | 12 h |
| September 28 | 76°F | 60°F | 31% | 20% | 12 h |
| September 29 | 75°F | 59°F | 31% | 20% | 12 h |
| September 30 | 75°F | 59°F | 31% | 20% | 11 h 50 min |
- Normal high
- 80°FSeptember average
- Normal low
- 64°FSeptember average
- Precipitation
- 4.49 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 28
- Days at 80°F or more
- 14
- Sunshine
- 77%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00075320; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lewes in September?
On a given September day the chance of 0.01 inch or more is 29% on average, highest around September 30 (31%). In all, 4.49 in falls on 9 days of a normal September, 1 of them with an inch or more.
In a normal September in Lewes, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00075320.
What are the records for September in Lewes?
The warmest September temperature on this station's record (since 1945) is 98°F, on September 12, 1983; the coldest is 37°F, on September 25, 1950. The wettest September brought 8.12 in (1999).
The September mean against the 1991-2020 normal of 71.7°F: 2021 71.5°F (−0.2), 2022 70.0°F (−1.7), 2023 70.5°F (−1.2), 2024 70.6°F (−1.1), 2025 70.6°F (−1.1). 0 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 71.5°F | −0.2°F | 2.35 in |
| 2022 | 70.0°F | −1.7°F | 3.12 in |
| 2023 | 70.5°F | −1.2°F | 6.45 in |
| 2024 | 70.6°F | −1.1°F | 0.42 in |
| 2025 | 70.6°F | −1.1°F | 3.34 in |
Source: records: ACIS, station USC00075320; recent months: ACIS, station USC00075320. Records and recent months use complete months only.
How does September in Lewes compare across Delaware?
Across the 6 places PlainClimate covers in Delaware, September normal highs run from 79°F in Wilmington to 80°F in Lewes; Lewes's is 80°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.