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
September brings a slight decrease in temperature, down from a moderately hot 85.1°F (29.5°C) in August to a still warm 78.1°F (25.6°C). Riverdale Park, in the month of September, anticipates a consistent average low-temperature of 62.2°F (16.8°C).Humidity
In Riverdale Park, the average relative humidity in September is 74%.Rainfall
In Riverdale Park, in September, it is raining for 12.3 days, with typically 2.09" (53mm) of accumulated precipitation. Throughout the year, in Riverdale Park, Maryland, there are 157.9 rainfall days, and 31.14" (791mm) of precipitation is accumulated.Snowfall
In Riverdale Park, snow does not fall in May through November.Daylight
In September, the average length of the day in Riverdale Park is 12h and 26min.On the first day of September, sunrise is at 6:37 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:51 pm EDT.
Sunshine
The average sunshine in September in Riverdale Park, Maryland, is 9.1h.UV index
In September, the average daily maximum UV index in Riverdale Park is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The daily high UV index of 5 in September translates into this advice:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Frequently asked questions
What are the temperatures in Riverdale Park in September?
What is the average humidity in September in Riverdale Park?
How many days does it rain in September in Riverdale Park?
When it does not snow in Riverdale Park?
How many hours of daylight does Riverdale Park have in September?
When is the sunrise / sunset in September in Riverdale Park?
How many hours of sunshine does Riverdale Park have in September?
What is the UV index intensity in September in Riverdale Park?
Average temperature in September
Riverdale Park, MD
- Average high temperature in September: 78.1°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.9°F).
- Average low temperature in September: 62.2°F
The month with the highest average low temperature is July (70°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).
Average pressure in September
Riverdale Park, MD
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Riverdale Park, MD
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Riverdale Park, MD
- Average humidity in September: 74%
The months with the highest relative humidity are May, October and December (76%).
The months with the lowest relative humidity are April and July (71%).
Average rainfall in September
Riverdale Park, MD
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is August (3.58").
The driest month (with the least rainfall) is January (2.01").
Average rainfall days in September
Riverdale Park, MD
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is November (9 days).
Average snowfall in September
Riverdale Park, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.6").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in September
Riverdale Park, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.1 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 Park, MD
- 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 30min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).
Average sunshine days in September
Riverdale Park, MD
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in September
Riverdale Park, MD
- 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 and December (UV index 2).
Average cloud cover in September
Riverdale Park, MD
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
Riverdale Park, MD
- 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 Park, Maryland, USA
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