September weather forecastMammoth Cave National Park, KY
September
Weather in September
As September approaches, Mammoth Cave National Park enjoys significant weather changes that mark the onset of fall. Temperature and daylight hours decrease noticeably, carrying mild and shorter days. Rainfall sustains its rhythm, keeping the park nourished and preparing it for the shifting season. With a declining UV index, sun exposure becomes more comfortable, enhancing outdoor experiences. September bridges summer's vibrancy with autumn's tranquility, marking an appealing time for explorers and nature lovers.Temperature
September is characterized by a mild reduction in the average high-temperature, from a tropical 86°F (30°C) in August to a warm 80.6°F (27°C). September nights in Mammoth Cave National Park bring a significant cooling from the heat of the day, with averages of 57.2°F (14°C).Rainfall
In Mammoth Cave National Park, in September, during 8 rainfall days, 3.74" (95mm) of precipitation is typically accumulated. Throughout the year, there are 126 rainfall days, and 50.63" (1286mm) of precipitation is accumulated.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Mammoth Cave National Park, Kentucky, sunrise is at 6:15 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 6:28 pm CDT.
Sunshine
The average sunshine in September is 8h.UV index
The average daily maximum UV index in September is 7. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 7 translates into these guidelines:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mammoth Cave National Park, KY
- Average high temperature in September: 81°F
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (41°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (23°F).
Average rainfall in September
Mammoth Cave National Park, KY
- Average rainfall in September: 3.7"
The wettest month (with the highest rainfall) is May (5").
The driest month (with the least rainfall) is October (3").
Average rainfall days in September
Mammoth Cave National Park, KY
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is March (13 days).
The months with the least rainy days are September and October (8 days).
Average daylight in September /
Average sunshine in September
Mammoth Cave National Park, KY
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 8h
The month with the most sunshine is June (Average sunshine: 10h).
The months with the least sunshine are January and December (Average sunshine: 4h).
Average UV index in September
Mammoth Cave National Park, KY
- Average UV index in September: 7
The months with the highest UV index are June and July (UV index 10).
The months with the lowest UV index are January and December (UV index 2).
