September weather forecastNew Castle, NH
September
Weather in September
September marks the transition from summer to fall in New Castle. The temperature begins to drop, but pleasant warmth continues to linger. While the frequency of rainfall increases once again, the overall precipitation sees a decline. Daylight hours begin to reduce, yet, the slight dip in sunshine hours does not affect the clarity of the days significantly.Temperature
September witnesses a gentle descent in average high-temperature, descending from August's warm 75.7°F (24.3°C) to an agreeable 69.1°F (20.6°C). The mean low-temperature during September nights is a refreshing 56.1°F (13.4°C).Humidity
The average relative humidity in September is 79%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.3 days and typically collects 1.54" (39mm) of precipitation.Snowfall
May through September are months without snowfall.Ocean temperature
In New Castle, in September, the average water temperature is 61.9°F (16.6°C).Note: For most individuals, swimming in 61.9°F (16.6°C) is not enjoyable. As the water temperature decreases from 69.8°F (21°C) to 59°F (15°C), breathing control becomes increasingly difficult.
Daylight
In September, the average length of the day in New Castle, New Hampshire, is 12h and 29min.On the first day of September in New Castle, sunrise is at 6:08 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 6:25 pm EDT.
Sunshine
The average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 4 suggests these recommendations:
Act with care - The need to guard against sun damage is communicated. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
New Castle, NH
- Average high temperature in September: 69.1°F
The warmest month (with the highest average high temperature) is July (76.3°F).
The month with the lowest average high temperature is January (31.8°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in September
New Castle, NH
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
New Castle, NH
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is January (11.7mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in September
New Castle, NH
- Average humidity in September: 79%
The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are April and November (75%).
Average rainfall in September
New Castle, NH
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in September
New Castle, NH
- Average rainfall days in September: 11.3 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in September
New Castle, NH
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
New Castle, NH
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature in September
New Castle, NH
- Average sea temperature in September: 61.9°F
The best month for swimming (with the highest average sea temperature) is August (65.6°F).
The coldest month (with the lowest average sea temperature) is March (38.5°F).
Average daylight in September /
Average sunshine in September
New Castle, NH
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in September
New Castle, NH
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is September (16.8 days).
The month with the least sunshine days is April (13.2 days).
Average UV index in September
New Castle, NH
- Average UV index in September: 4
The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
New Castle, NH
- Average cloud cover in September: 33
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
New Castle, NH
- 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).
