Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The average high-temperature in New Castle slightly decreases in September, shifting from a warm 82.9°F (28.3°C) in August to a still moderately hot 76.3°F (24.6°C). New Castle experiences a nighttime temperature average of 60.6°F (15.9°C) during September.Humidity
In September, the average relative humidity in New Castle, Delaware, is 77%.Rainfall
In New Castle, during September, the rain falls for 11.2 days and regularly aggregates up to 1.42" (36mm) of precipitation. Throughout the year, there are 143.2 rainfall days, and 21.89" (556mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in New Castle.Ocean temperature
In September, the average ocean temperature is 72.1°F (22.3°C).Note: A person's cold intolerance, with sunshine, wind, and air temperature, are essential factors for enjoying swimming in 72.1°F (22.3°C) water. (FYI: The Olympic swimming competition requires a water temperature between 77°F (25°C) and 82.4°F (28°C).)
Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:45 pm EDT.
Sunshine
The average sunshine in September in New Castle is 9.2h.UV index
In New Castle, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Take precautions - Protection against sun damage is advised. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Be cautious! Sand and water surfaces make the Sun's UV rays more potent.
Frequently asked questions
What are September temperatures in New Castle?
What is the average humidity in September in New Castle?
How much does it rain in New Castle in September?
When it does not snow in New Castle?
What is the ocean temperature in September in New Castle?
What is the average length of the day in September in New Castle?
When are sunrise and sunset in September in New Castle?
How many hours of sunshine does New Castle have in September?
How high is the UV index in September in New Castle?
Average temperature in September
New Castle, DE
- Average high temperature in September: 76.3°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in September: 60.6°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in September
New Castle, DE
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
New Castle, DE
- Average wind speed in September: 6mph
The windiest months (with the highest average wind speed) are February and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
New Castle, DE
- Average humidity in September: 77%
The month with the highest relative humidity is October (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
New Castle, DE
- Average rainfall in September: 1.42"
The wettest month (with the highest rainfall) is August (2.83").
The driest month (with the least rainfall) is January (1.38").
Average rainfall days in September
New Castle, DE
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
New Castle, DE
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.69").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
New Castle, DE
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
New Castle, DE
- Average sea temperature in September: 72.1°F
The best month for swimming (with the highest average sea temperature) is August (76.3°F).
The coldest month (with the lowest average sea temperature) is February (40.9°F).
Average daylight in September /
Average sunshine in September
New Castle, DE
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in September
New Castle, DE
- Average sunshine days in September: 17.6 days
The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in September
New Castle, DE
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
New Castle, DE
- Average cloud cover in September: 35
The months with the most cloud cover are February and March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
New Castle, DE
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
New Castle, Delaware, USA
Weather forecast for your location
2. Allow the app to use your location
