September weather forecastMonmouth Junction, NJ
September
Weather in September
September, the first month of the autumn in Monmouth Junction, is also a moderately hot month, with an average temperature ranging between min 59°F (15°C) and max 75.7°F (24.3°C).Temperature
Transitioning from August to September involves a subtle drop in average high-temperatures, descending from 82.9°F (28.3°C) to a still warm 75.7°F (24.3°C). In the month of September, the average low-temperature usually rests at a refreshing 59°F (15°C).Humidity
The average relative humidity in September is 77%.Rainfall
The month with the least rainfall is September, when the rain falls for 10 days and typically collects 0.67" (17mm) of precipitation.Snowfall
June through October are months without snowfall in Monmouth Junction.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:54 am and sunset at 6:41 pm EDT.
Sunshine
In Monmouth Junction, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Monmouth Junction, NJ
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in September: 59°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Monmouth Junction, 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
Monmouth Junction, NJ
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
Monmouth Junction, NJ
- Average humidity in September: 77%
The month with the highest relative humidity is October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Monmouth Junction, NJ
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is July (1.69").
The driest month (with the least rainfall) is September (0.67").
Average rainfall days in September
Monmouth Junction, NJ
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is January (6.1 days).
Average snowfall in September
Monmouth Junction, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.42").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Monmouth Junction, NJ
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Monmouth Junction, 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 18min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Monmouth Junction, NJ
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is January (21.8 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in September
Monmouth Junction, NJ
- Average UV index in September: 4
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
Monmouth Junction, NJ
- Average cloud cover in September: 38
The months with the most cloud cover are February, March and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Monmouth Junction, NJ
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).





