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
September heralds a minor drop in average high-temperature, sliding from August's 82.2°F (27.9°C) to a still moderately hot 76.8°F (24.9°C). Raritan, in September, observes a steady average low-temperature of 57.4°F (14.1°C).Humidity
In Raritan, the average relative humidity in September is 75%.Rainfall
In September, the rain falls for 10.2 days. Throughout September, 1.77" (45mm) of precipitation is accumulated. Throughout the year, there are 127.6 rainfall days, and 21.02" (534mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:35 pm. On the last day of September, in Raritan, sunrise is at 6:59 am and sunset at 6:46 pm CDT.
Sunshine
In Raritan, the average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: In September, a regular UV index of 5 translates into these guidelines:
Ensure safety - Recommendations to avert sunburn are presented. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September in Raritan?
How many hours of sunshine does Raritan have in September?
What is the UV index reading in September?
Average temperature in September
Raritan, IL
- Average high temperature in September: 76.8°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (30.9°F).
- Average low temperature in September: 57.4°F
The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).
Average pressure in September
Raritan, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Raritan, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.7mph).
Average humidity in September
Raritan, 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
Raritan, IL
- Average rainfall in September: 1.77"
The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is January (0.83").
Average rainfall days in September
Raritan, IL
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (4.3 days).
Average snowfall in September
Raritan, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.15").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Raritan, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.5 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
Raritan, IL
- Average daylight in September: 12h and 2min
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 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Raritan, IL
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is December (20 days).
The months with the least sunshine days are May and June (11.8 days).
Average UV index in September
Raritan, IL
- 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
Raritan, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 30).
Average visibility in September
Raritan, 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).
Raritan, Illinois, USA
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