September weather forecastYellowstone, IN
September
Weather in September
The first month of the autumn, September, is still a warm month in Yellowstone, Indiana, with an average temperature ranging between max 78.3°F (25.7°C) and min 58.5°F (14.7°C).Temperature
The transition to September results in a modest reduction in average high-temperature, moving from a warm 84.2°F (29°C) in August to a still moderately hot 78.3°F (25.7°C). Yellowstone, during September, witnesses an average low-temperature of 58.5°F (14.7°C).Humidity
In Yellowstone, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.2 days and typically collects 0.91" (23mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September in Yellowstone is 12h and 26min.On the first day of the month, sunrise is at 7:14 am and sunset at 8:15 pm. On the last day of September, sunrise is at 7:41 am and sunset at 7:29 pm EDT.
Sunshine
The average sunshine in September in Yellowstone is 8.3h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The UV index of 5 during September translates into the following guidance:
Adopt protective measures - It is advised to guard against sun damage. The Sun's radiation is especially intense around midday; try to stay in shade 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
Average temperature in September
Yellowstone, IN
- Average high temperature in September: 78.3°F
The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in September
Yellowstone, IN
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Yellowstone, IN
- Average wind speed in September: 5.5mph
The windiest months (with the highest average wind speed) are January, February and April (7.8mph).
The calmest months (with the lowest average wind speed) are July and August (4.9mph).
Average humidity in September
Yellowstone, IN
- Average humidity in September: 76%
The months with the highest relative humidity are February, May and December (81%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Yellowstone, IN
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is July (2.17").
The driest month (with the least rainfall) is September (0.91").
Average rainfall days in September
Yellowstone, IN
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is May (15.8 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Yellowstone, IN
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.22").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Yellowstone, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Yellowstone, IN
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 8h and 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days in September
Yellowstone, IN
- Average sunshine days in September: 16.6 days
The month with the most sunshine days is October (21.2 days).
The month with the least sunshine days is May (12.1 days).
Average UV index in September
Yellowstone, IN
- Average UV index in September: 5
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, November and December (UV index 2).
Average cloud cover in September
Yellowstone, IN
- Average cloud cover in September: 34
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Yellowstone, IN
- Average visibility in September: 5mi
The months with the highest visibility are March, April, October and November (6mi).
The months with the lowest visibility are January, February, May, June, July, August, September and December (5mi).





