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United StatesThe weather in September in Delaware
It's warm in September in Delaware with an average temperature of 26°C. Temperatures this month range from a low of 22°C to a high of 30°C. At night, you can expect temperatures between 15°C and 21°C.
Looking for sun? September isn’t a good month to be in Delaware. The temperature is nice, but there’s too much chance of rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Delaware, United States. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 35°C in 2016, Delaware reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 17°C in 2023. The extreme nighttime temperatures ranged from a lowest recorded value of 8°C to a highest value of 26°C.
Rainfall amount
In September, there is an average of 117 mm of precipitation, spread over 14 days. The wind speed is around 4 Bft, mostly coming from the Southeast.
Daily weather in September for Delaware
Click on any day in September to get detailed info about the usual weather on that day in Delaware. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Delaware | New York | |
|---|---|---|
| Average temperature | 26°C | 27°C |
| Max. temperature | 30°C | 31°C |
| Min. temperature | 15°C | -5°C |
| Total precipitation | 117 mm | 57 mm |
| Rainy days | 14 days | 9 days |
Start of September
The month of September starts in Delaware with hot temps, averaging around 29°C during the day and nights around 20°C.
Mid September
By mid-September, daytime temps drop to around 27°C, with nights around 18°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Delaware is around 25°C, while nighttime temps are about 17°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.
UV index
The UV index is a maximum of 6 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Check out the climate of Delaware for all months and discover the best travel time
The climate in Delaware is based on weather data from . Other places, like New York City, Miami or Los Angeles, might have different weather. You can check out all destinations in Delaware to get the full picture of the climate.
Temperature charts
These charts show the average temperatures in September in Delaware, United States. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Delaware
Temperature in September in Delaware over the years
Precipitation charts
These charts show the average amount of precipitation in September in Delaware, United States. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Delaware
Total precipitation in September in Delaware over the years
Daily UV index in September in Delaware
This chart shows the average daily UV index in September in Delaware, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Delaware
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Average weather in Delaware by month
Click on a month below to see detailed weather info for Delaware. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.