Dover, DE weather in September
Dover is mild and often humid in September, with some rain: highs average 79°F and nights drop to about 61°F. There are about 8 days with rain. A good month for most outdoor plans.
- Normal high
- 79°F
- Normal low
- 61°F
- Wet days
- 8
- 4.3 in total
- Muggy days
- 11
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 83°F | 75°F |
| Normal low | 65°F | 56°F |
| Chance of a wet day | 25% | 28% |
| Sunrise / sunset | 6:30 am / 7:33 pm | 6:57 am / 6:46 pm |
| Daylight | 13.0 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical September day
- 6 am63°Fdew point 60°F
- 9 am71°Fdew point 62°F
- Noon75°Fdew point 61°F
- 3 pm76°Fdew point 60°F
- 6 pm71°Fdew point 61°F
- 9 pm67°Fdew point 61°F
NOAA hourly normals (local standard time) from Dover AFB (4 mi away); average wind 8 mph; clear or few clouds in 49% of daytime hours, mostly cloudy or overcast in 38%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F10 of 30
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph12 of 30
- Hot dayshigh 90°F or more2 of 30
- Muggy daysdaily mean dew point 65°F or more11 of 30
- Wet daysat least 0.01 in of rain or melted snow8 of 30
- Notable rainat least 0.10 in6 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 4.3 in; a dry September brings about 2.5 in and a wet one about 5.8 in (25th and 75th percentiles). About 3 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202010: average high 84°F
- Coolest September2000: average high 75°F
- Wettest September1999: 10.5 in
- Driest September2005: 0.3 in
- Highest reading95°F (September 10, 2016)
- Lowest reading42°F (September 28, 1991)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 85°F | 79°F | 69°F |
| Normal low | 67°F | 61°F | 50°F |
| Wet days | 8 | 8 | 8 |
| Comfortable days | 2 | 10 | 16 |
| Daylight | 13.7 h | 12.4 h | 11.2 h |
Highs change by -6°F from August and -10°F into October.
Nearby alternatives in September
- Cooler: Stamford, CT168 mi · high 74°F · 10 wet days
How Dover ranks in September
- Normal high207th warmest of 378 cities; 1st of 2 in Delaware
- Wet days204th driest of 378
- Comfortable days157th most of 342
What to pack for Dover in September
- A rain jacket or umbrella – rain on about 8 days
- A swimsuit – about 12 beach days
Heating and cooling
September has 26 heating degree days and 179 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Dover in September?
The normal high is 79°F and the normal low is 61°F. From 1991 to 2020 the hottest September reading was 95°F (most recently on September 10, 2016).
Does it rain a lot in Dover in September?
About 8 days in September have at least 0.01 in of precipitation, and the normal total is 4.3 in. The wettest September in 1991-2020 was in 1999 (10.5 in); the driest was in 2005 (0.3 in).
Is September a good time to visit Dover?
September ranks 4th of 12 months on our comfort score for Dover (61 out of 100). It has about 10 comfortable days and about 2 days at 90°F or hotter. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth and frost dates: Dover (USC00072730), 1.3 mi SE of the city center, 30 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Dover AFB (USW00013707), 3.5 mi ESE of the city center, 23 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Dover AFB Airport (724088-13707), 3.5 mi ESE of the city center, 28 ft . Hourly observations, 1991-2020.