September weather forecastErwin, SD
September
Weather in September
September, the first month of the autumn in Erwin, is also an agreeable month, with an average temperature ranging between max 71.6°F (22°C) and min 51.3°F (10.7°C).Temperature
The move into September indicates a slight reduction in the average high-temperature, down from August's warm 80.1°F (26.7°C) to a pleasant 71.6°F (22°C). September in Erwin sees the temperature falling to a mean low of 51.3°F (10.7°C).Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 68%.Rainfall
In September, in Erwin, South Dakota, the rain falls for 10.4 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. In Erwin, during the entire year, the rain falls for 112.3 days and collects up to 18.78" (477mm) of precipitation.Snowfall
June through September are months without snowfall in Erwin.Daylight
In September, the average length of the day is 12h and 30min.On the first day of September, sunrise is at 6:53 am and sunset at 8:05 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 in Erwin is 8.8h.UV index
The average daily maximum UV index in September in Erwin is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 4 in September transforms into this advice:
Make use of precautions - Suggestions to resist sunburn are communicated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Erwin, SD
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (19.4°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (5.5°F).
Average pressure in September
Erwin, SD
- Average pressure in September: 29.97"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
Erwin, SD
- Average wind speed in September: 10mph
The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.5mph).
Average humidity in September
Erwin, SD
- Average humidity in September: 68%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are September and October (68%).
Average rainfall in September
Erwin, SD
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is June (3.19").
The driest months (with the least rainfall) are January and February (0.59").
Average rainfall days in September
Erwin, SD
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (2.7 days).
Average snowfall in September
Erwin, SD
- Average snowfall in September: 0"
The months with the highest snowfall are January and December (3.74").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Erwin, SD
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Erwin, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 8h and 48min
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 36min).
Average sunshine days in September
Erwin, SD
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Erwin, 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 and December (UV index 1).
Average cloud cover in September
Erwin, SD
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Erwin, 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).
