Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
In September, the average high-temperature registers at a still moderately hot 75.9°F (24.4°C), nearly identical to August's 81.1°F (27.3°C). During September, Monmouth experiences a consistent low-temperature average of 56.3°F (13.5°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Monmouth, during September, the rain falls for 11.6 days and regularly aggregates up to 2.4" (61mm) of precipitation. In Monmouth, during the entire year, the rain falls for 149.4 days and collects up to 30.16" (766mm) of precipitation.Snowfall
In Monmouth, snow does not fall in May through September.Daylight
In Monmouth, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:45 pm CDT.
Sunshine
In September, the average sunshine is 9.4h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.Note: During September, 4 as the daily maximum UV index converts into the following advice:
Exercise caution. Those with pale skin may experience burns in less than half an hour. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow in Monmouth?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Monmouth, IL
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.6°F).
Average pressure in September
Monmouth, 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 (29.9"Hg).
Average wind speed in September
Monmouth, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Monmouth, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Monmouth, IL
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is May (4.25").
The driest month (with the least rainfall) is January (1.46").
Average rainfall days in September
Monmouth, IL
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is February (5.8 days).
Average snowfall in September
Monmouth, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.61").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Monmouth, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.9 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
Monmouth, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Monmouth, IL
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is June (9.2 days).
Average UV index in September
Monmouth, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Monmouth, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 30).
Average visibility in September
Monmouth, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Monmouth, Illinois, USA
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