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 shift from August to September includes a small decrease in the average high-temperature, from a hot 86.2°F (30.1°C) to a moderately hot 80.1°F (26.7°C). During September nights, Rockwood records an average temperature of 59.9°F (15.5°C).Humidity
In Rockwood, the average relative humidity in September is 74%.Rainfall
The month with the least rainfall is September, when the rain falls for 8.6 days and typically collects 0.43" (11mm) of precipitation.Snowfall
In Rockwood, Illinois, snow does not fall in April through September.Daylight
The average length of the day in September in Rockwood is 12h and 25min.On the first day of September, sunrise is at 6:29 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:42 pm CDT.
Sunshine
In Rockwood, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Take precautions - Protection against skin and eye damage is obliged. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. To cut down UV radiation exposure by about half, sport a wide-brim 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?
What is the driest month?
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?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September in Rockwood?
Average temperature in September
Rockwood, IL
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.4°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in September
Rockwood, 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
Rockwood, IL
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in September
Rockwood, IL
- Average humidity in September: 74%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Rockwood, IL
- Average rainfall in September: 0.43"
The wettest months (with the highest rainfall) are April and May (1.22").
The driest month (with the least rainfall) is September (0.43").
Average rainfall days in September
Rockwood, IL
- Average rainfall days in September: 8.6 days
The month with the highest number of rainy days is July (13.4 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in September
Rockwood, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.59").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Rockwood, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.7 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
Rockwood, IL
- Average daylight in September: 12h and 2min
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 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 48min).
Average sunshine days in September
Rockwood, IL
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is October (21.9 days).
The month with the least sunshine days is July (13.5 days).
Average UV index in September
Rockwood, 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 and December (UV index 2).
Average cloud cover in September
Rockwood, IL
- Average cloud cover in September: 28
The months with the most cloud cover are January and February (Cloud cover 48).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
Rockwood, 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).
Rockwood, Illinois, USA
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