September weather forecastLetcher, SD
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Letcher, South Dakota, with an average temperature fluctuating between 76.1°F (24.5°C) and 55°F (12.8°C).Temperature
In the transition to September, Letcher observes a minor drop in the average high-temperature, shifting from a moderately hot 84.4°F (29.1°C) in August to a still warm 76.1°F (24.5°C). Nighttime temperatures hover around an average low of 55°F (12.8°C) in September.Humidity
September and October, with an average relative humidity of 63%, are the least humid months.Rainfall
In September, the rain falls for 9.2 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. In Letcher, during the entire year, the rain falls for 93.2 days and collects up to 11.3" (287mm) of precipitation.Snowfall
In Letcher, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:56 am and sunset at 8:07 pm. On the last day of September, sunrise is at 7:29 am and sunset at 7:14 pm CDT.
Sunshine
In Letcher, the average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: A daily maximum UV index of 5 in September translates into the following instructions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Around midday, solar radiation is most harmful; hence, exposure should be limited. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Letcher, SD
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (24.4°F).
- Average low temperature in September: 55°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (10.2°F).
Average pressure in September
Letcher, SD
- Average pressure in September: 29.96"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Letcher, SD
- Average wind speed in September: 9.7mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).
Average humidity in September
Letcher, SD
- Average humidity in September: 63%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in September
Letcher, SD
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are February and November (0.28").
Average rainfall days in September
Letcher, SD
- Average rainfall days in September: 9.2 days
The month with the highest number of rainy days is June (13.6 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in September
Letcher, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.42").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Letcher, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Letcher, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 54min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Letcher, SD
- Average sunshine days in September: 18.3 days
The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in September
Letcher, SD
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Letcher, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in September
Letcher, SD
- 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).
