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
The initiation of September sees an average high-temperature of a warm 83.8°F (28.8°C), showing minor variations from the previous month. The nights of September in Riverdale anticipate an average low-temperature of 65.7°F (18.7°C).Heat index
September's average heat index is appraised at a hot 91.4°F (33°C). Incorporate additional preventive steps, heat exhaustion and heat cramps are possible. Long-lasting activity may cause heatstroke.Heat index determinations are made taking into account the shade and light air movements. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', gives an indication of how one might feel in terms of heat after considering humidity. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
Humidity
In September, the average relative humidity is 72%.Rainfall
In Riverdale, in September, during 13.3 rainfall days, 2.72" (69mm) of precipitation is typically accumulated. In Riverdale, during the entire year, the rain falls for 181.2 days and collects up to 41.06" (1043mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 7:12 am and sunset at 8:02 pm. On the last day of September, sunrise is at 7:31 am and sunset at 7:22 pm EDT.
Sunshine
In Riverdale, the average sunshine in September is 8.5h.UV index
May through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for the ordinary person.Note: The average daily UV index of 6 in September transforms into the following instructions:
Follow precautions and abide by sun safety rules. Deterrence of sunburn is imperative. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index?
How high is the UV index in September?
Average temperature in September
Riverdale, GA
- Average high temperature in September: 83.8°F
The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (51.3°F).
- Average low temperature in September: 65.7°F
The month with the highest average low temperature is July (71.1°F).
The coldest month (with the lowest average low temperature) is January (35.6°F).
Average pressure in September
Riverdale, GA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in September
Riverdale, GA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is January (8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Riverdale, GA
- Average humidity in September: 72%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Riverdale, GA
- Average rainfall in September: 2.72"
The wettest month (with the highest rainfall) is August (5.43").
The driest month (with the least rainfall) is October (2.17").
Average rainfall days in September
Riverdale, GA
- Average rainfall days in September: 13.3 days
The month with the highest number of rainy days is July (22.8 days).
The month with the least rainy days is November (9.6 days).
Average snowfall in September
Riverdale, GA
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.47").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Riverdale, GA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.2 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, GA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 8h and 3min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
Riverdale, GA
- Average sunshine days in September: 15.3 days
The month with the most sunshine days is October (20.1 days).
The month with the least sunshine days is July (7.2 days).
Average UV index in September
Riverdale, GA
- Average UV index in September: 6
The months with the highest UV index are May, June, July, August and September (UV index 6).
The months with the lowest UV index are January, February and December (UV index 3).
Average cloud cover in September
Riverdale, GA
- Average cloud cover in September: 32
The month with the most cloud cover is December (Cloud cover 47).
The months with the least cloud cover are June and October (Cloud cover 31).
Average visibility in September
Riverdale, GA
- 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, Georgia, USA
Weather forecast for your location
2. Allow the app to use your location