September weather forecastRobertsville, NJ
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Robertsville, New Jersey, with temperature in the range of an average low of 62.2°F (16.8°C) and an average high of 74.7°F (23.7°C).Temperature
The shift from August to September includes a small decrease in the average high-temperature, from a warm 81.1°F (27.3°C) to a still moderately hot 74.7°F (23.7°C). Robertsville's nighttime temperature in September falls to an average of 62.2°F (16.8°C).Humidity
In Robertsville, the average relative humidity in September is 76%.Rainfall
September is the month with the least rainfall in Robertsville. Rain falls for 13.2 days and accumulates 1.69" (43mm) of precipitation.Snowfall
In Robertsville, snow does not fall in May through September.Daylight
In Robertsville, New Jersey, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:28 pm. On the last day of September, in Robertsville, sunrise is at 6:53 am and sunset at 6:40 pm EDT.
Sunshine
The average sunshine in September in Robertsville is 9h.UV index
In September, the average daily maximum UV index in Robertsville, New Jersey, is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index of 5 during September translates into these guidelines:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Robertsville, NJ
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in September: 62.2°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in September
Robertsville, NJ
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Robertsville, NJ
- Average wind speed in September: 7.4mph
The windiest months (with the highest average wind speed) are January and March (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).
Average humidity in September
Robertsville, NJ
- Average humidity in September: 76%
The months with the highest relative humidity are May and June (78%).
The months with the lowest relative humidity are January, March, April, August and November (74%).
Average rainfall in September
Robertsville, NJ
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.69").
Average rainfall days in September
Robertsville, NJ
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is July (16.4 days).
The months with the least rainy days are January and November (9.8 days).
Average snowfall in September
Robertsville, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.4").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Robertsville, NJ
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Robertsville, NJ
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in September
Robertsville, NJ
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (18.3 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Robertsville, NJ
- Average UV index in September: 5
The months with the highest UV index are June, 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
Robertsville, NJ
- Average cloud cover in September: 34
The months with the most cloud cover are February and March (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 29).
Average visibility in September
Robertsville, NJ
- 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).





