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
The start of September sees the average high-temperature at a still moderately hot 76.8°F (24.9°C), showing little difference from August's 82°F (27.8°C). Throughout September nights, Colchester registers an average low-temperature of 57.6°F (14.2°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In September, the rain falls for 7.7 days. Throughout September, 0.87" (22mm) of precipitation is accumulated. Throughout the year, there are 94.4 rainfall days, and 7.76" (197mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:34 pm. On the last day of September, in Colchester, sunrise is at 6:59 am and sunset at 6:46 pm CDT.
Sunshine
In Colchester, the average sunshine in September is 9.4h.UV index
In Colchester, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Undertake protective steps - Preventing sun damage is advised. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Frequently asked questions
What are September temperatures in Colchester?
What is the average humidity in September in Colchester?
How many days does it rain in September in Colchester?
When it does not snow in Colchester?
Does it snow in Colchester in September?
How many hours of daylight does Colchester have in September?
What time are sunrise and sunset in September in Colchester?
How many hours of sunshine does Colchester have in September?
What is the UV index reading in September in Colchester?
Average temperature in September
Colchester, 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 (31.1°F).
- Average low temperature in September: 57.6°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 (19°F).
Average pressure in September
Colchester, 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
Colchester, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is January (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Colchester, 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
Colchester, IL
- Average rainfall in September: 0.87"
The wettest month (with the highest rainfall) is May (1.1").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in September
Colchester, IL
- Average rainfall days in September: 7.7 days
The month with the highest number of rainy days is May (12.3 days).
The month with the least rainy days is January (3.3 days).
Average snowfall in September
Colchester, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.67").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Colchester, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.3 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
Colchester, 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 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Colchester, IL
- Average sunshine days in September: 20.4 days
The month with the most sunshine days is December (23.5 days).
The month with the least sunshine days is June (13.9 days).
Average UV index in September
Colchester, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Colchester, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Colchester, 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).
Colchester, Illinois, USA
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