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 arrival of September suggests a slight decrease in the average high-temperature, moving from 83.1°F (28.4°C) in August to a still warm 74.3°F (23.5°C). During the month of September, an average temperature of 52.9°F (11.6°C) is noted during the nights.Humidity
The months with the lowest humidity are August and September, with an average relative humidity of 60%.Rainfall
In September, the rain falls for 8.9 days. Throughout September, 1.26" (32mm) of precipitation is accumulated. Throughout the year, in Groton, there are 97.2 rainfall days, and 18.35" (466mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Groton, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:54 am and sunset at 8:09 pm. On the last day of September, sunrise is at 7:30 am and sunset at 7:13 pm CDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In Groton, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Exercise prevention - Precautions against solar damage are endorsed. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the least humid month?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Groton have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Groton, SD
- Average high temperature in September: 74.3°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 (20.7°F).
- Average low temperature in September: 52.9°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (6.3°F).
Average pressure in September
Groton, SD
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Groton, SD
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Groton, SD
- Average humidity in September: 60%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are August and September (60%).
Average rainfall in September
Groton, SD
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is June (3.46").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Groton, SD
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is February (2 days).
Average snowfall in September
Groton, SD
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.82").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Groton, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Groton, SD
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Groton, SD
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is June (12.7 days).
Average UV index in September
Groton, SD
- 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 and November (UV index 1).
Average cloud cover in September
Groton, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 23).
Average visibility in September
Groton, SD
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Groton, South Dakota, USA
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