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
With the commencement of September, Grenville records a moderate temperature decline, with the average high easing from August's moderately hot 80.1°F (26.7°C) to an agreeable 71.6°F (22°C). In Grenville, the average low-temperature during the month of September is a fresh 51.3°F (10.7°C).Humidity
The least humid month in Grenville is September, with an average relative humidity of 66%.Rainfall
In Grenville, during September, the rain falls for 10.1 days and regularly aggregates up to 1.57" (40mm) of precipitation. In Grenville, South Dakota, during the entire year, the rain falls for 112.9 days and collects up to 22.09" (561mm) of precipitation.Snowfall
In Grenville, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 31min.On the first day of September in Grenville, South Dakota, sunrise is at 6:52 am and sunset at 8:06 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 7:11 pm CDT.
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 unprotected exposure to Sun's UV rays for the ordinary person.Note: A daily high UV index of 4 in September leads to these guidelines:
Heed the precautions - Suggestions to avoid sunburn are made. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the least humid month?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Grenville, SD
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (18.9°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (5°F).
Average pressure in September
Grenville, 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
Grenville, SD
- Average wind speed in September: 10.3mph
The windiest month (with the highest average wind speed) is April (11.7mph).
The calmest month (with the lowest average wind speed) is July (8.7mph).
Average humidity in September
Grenville, SD
- Average humidity in September: 66%
The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is September (66%).
Average rainfall in September
Grenville, SD
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is July (3.58").
The driest month (with the least rainfall) is November (0.63").
Average rainfall days in September
Grenville, SD
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (2.3 days).
Average snowfall in September
Grenville, SD
- Average snowfall in September: 0"
The month with the highest snowfall is December (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grenville, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grenville, 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 5min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 12min).
Average sunshine days in September
Grenville, SD
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in September
Grenville, SD
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Grenville, SD
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 66).
The months with the least cloud cover are July and August (Cloud cover 27).
Average visibility in September
Grenville, SD
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March and December (5mi).
Grenville, South Dakota, USA
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