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 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
A mild drop in Riverdale's average high-temperature is observed in September, transitioning from 82.6°F (28.1°C) in August to a still moderately hot 75.2°F (24°C). Riverdale reports an average nighttime low-temperature of 60.8°F (16°C) in September.Humidity
In September, the average relative humidity in Riverdale is 73%.Rainfall
September is the month with the least rainfall. Rain falls for 8.1 days and accumulates 0.39" (10mm) of precipitation.Snowfall
In Riverdale, snow does not fall in May through November.Daylight
In Riverdale, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:24 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:40 pm EDT.
Sunshine
In September, the average sunshine is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In September, a regular UV index of 4 translates into these guidelines:
Adopt protective measures - It is advised to guard against sun damage. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Riverdale?
What is the average humidity in September in Riverdale?
What is the driest month in Riverdale?
How much does it rain in Riverdale in September?
When it does not snow in Riverdale?
What is the average length of the day in September in Riverdale?
When are sunrise and sunset in September in Riverdale?
How many hours of sunshine does Riverdale have in September?
What is the UV index reading in September in Riverdale?
Average temperature in September
Riverdale, NJ
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.8°F).
- Average low temperature in September: 60.8°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in September
Riverdale, NJ
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Riverdale, NJ
- Average wind speed in September: 6.7mph
The windiest month (with the highest average wind speed) is January (9mph).
The calmest month (with the lowest average wind speed) is July (6.1mph).
Average humidity in September
Riverdale, NJ
- Average humidity in September: 73%
The months with the highest relative humidity are February and December (76%).
The month with the lowest relative humidity is August (69%).
Average rainfall in September
Riverdale, NJ
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is July (0.98").
The driest month (with the least rainfall) is September (0.39").
Average rainfall days in September
Riverdale, NJ
- Average rainfall days in September: 8.1 days
The month with the highest number of rainy days is May (11.4 days).
The month with the least rainy days is January (5.4 days).
Average snowfall in September
Riverdale, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.35").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in September
Riverdale, NJ
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (3.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Riverdale, NJ
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 5min
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 42min).
Average sunshine days in September
Riverdale, NJ
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is January (22.5 days).
The months with the least sunshine days are May and June (15.9 days).
Average UV index in September
Riverdale, 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
Riverdale, NJ
- Average cloud cover in September: 35
The months with the most cloud cover are February, March and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Riverdale, 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).
Riverdale, New Jersey, USA
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