September weather forecastRoyalton, IL
September
Weather in September
September, the first month of the autumn in Royalton, is still a warm month, with an average temperature ranging between min 60.3°F (15.7°C) and max 80.4°F (26.9°C).Temperature
The move into September indicates a slight reduction in the average high-temperature, down from August's 85.8°F (29.9°C) to a still warm 80.4°F (26.9°C). During September, Royalton observes a consistent average nighttime temperature of 60.3°F (15.7°C).Humidity
In Royalton, Illinois, the average relative humidity in September is 73%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.7 days and typically collects 1.85" (47mm) of precipitation.Snowfall
In Royalton, snow does not fall in May through September.Daylight
In Royalton, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:25 pm. On the last day of September, in Royalton, sunrise is at 6:51 am and sunset at 6:40 pm CDT.
Sunshine
The average sunshine in September is 9.5h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The daily high UV index of 5 during September translates into the following recommendations:
Prioritize safety - Suggestions to prevent sun damage are offered. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Royalton, IL
- Average high temperature in September: 80.4°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.6°F).
- Average low temperature in September: 60.3°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in September
Royalton, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Royalton, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in September
Royalton, IL
- Average humidity in September: 73%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Royalton, IL
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is April (4.49").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in September
Royalton, IL
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in September
Royalton, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Royalton, IL
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (4.8 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
Royalton, IL
- 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 36min).
- Average sunshine in September: 9h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Royalton, IL
- Average sunshine days in September: 16 days
The month with the most sunshine days is October (18.5 days).
The month with the least sunshine days is May (11.3 days).
Average UV index in September
Royalton, IL
- Average UV index in September: 5
The months with the highest UV index are May, 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
Royalton, IL
- Average cloud cover in September: 28
The month with the most cloud cover is February (Cloud cover 50).
The months with the least cloud cover are June and August (Cloud cover 27).
Average visibility in September
Royalton, IL
- 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).
