September weather forecastLewistown, IL
September
Weather in September
September, the first month of the autumn in Lewistown, is also a moderately hot month, with temperature in the range of an average high of 76.6°F (24.8°C) and an average low of 57.6°F (14.2°C).Temperature
The beginning of September brings a slight decrease in the average high-temperature, transitioning from a warm 82°F (27.8°C) in August to a still moderately hot 76.6°F (24.8°C). Lewistown's temperature lowers to a mean of 57.6°F (14.2°C) during the nights in September.Humidity
The average relative humidity in September is 75%.Rainfall
In Lewistown, in September, it is raining for 11 days, with typically 2.09" (53mm) of accumulated precipitation. In Lewistown, during the entire year, the rain falls for 131.7 days and collects up to 22.48" (571mm) of precipitation.Snowfall
In Lewistown, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:28 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:43 pm CDT.
Sunshine
In Lewistown, the average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Preventative actions are necessary - Recommendations to ward off sunburn are given. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lewistown, IL
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (31.5°F).
- Average low temperature in September: 57.6°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 (19.4°F).
Average pressure in September
Lewistown, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Lewistown, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.5mph).
Average humidity in September
Lewistown, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Lewistown, IL
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is December (0.94").
Average rainfall days in September
Lewistown, IL
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is February (4.7 days).
Average snowfall in September
Lewistown, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.35").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Lewistown, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.4 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
Lewistown, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Lewistown, IL
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in September
Lewistown, IL
- Average UV index in September: 4
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
Lewistown, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in September
Lewistown, 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).





