August weather forecastPrinceton, IL
August
Weather in August
The last month of the summer, August, is also a moderately hot month in Princeton, Illinois, with an average temperature fluctuating between 62.1°F (16.7°C) and 79.5°F (26.4°C).Temperature
Princeton sees the arrival of August with an average high-temperature of a still warm 79.5°F (26.4°C), indicating a subtle variation from July. Throughout August, Princeton witnesses a consistent average low-temperature of 62.1°F (16.7°C).Humidity
In Princeton, the average relative humidity in August is 83%.Rainfall
In Princeton, in August, during 12.8 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. Throughout the year, there are 130 rainfall days, and 17.64" (448mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in August in Princeton is 13h and 47min.On the first day of August, sunrise is at 5:53 am and sunset at 8:14 pm. On the last day of the month, sunrise is at 6:23 am and sunset at 7:31 pm CDT.
Sunshine
In Princeton, the average sunshine in August is 9.6h.UV index
In Princeton, Illinois, the average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: The daily maximum UV index of 5 in August interprets into the following advice:
Guard yourself - Precautionary measures against sun damage are advocated. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Princeton, IL
- Average high temperature in August: 79.5°F
The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in August: 62.1°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in August
Princeton, IL
- Average pressure in August: 29.97"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in August
Princeton, IL
- Average wind speed in August: 6.4mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in August
Princeton, IL
- Average humidity in August: 83%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in August
Princeton, IL
- Average rainfall in August: 1.5"
The wettest month (with the highest rainfall) is May (2.91").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in August
Princeton, IL
- Average rainfall days in August: 12.8 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (4.5 days).
Average snowfall in August
Princeton, IL
- Average snowfall in August: 0"
The month with the highest snowfall is January (2.09").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Princeton, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (10.4 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in August /
Average sunshine in August
Princeton, IL
- Average daylight in August: 13h and 48min
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 12min).
- Average sunshine in August: 9h and 36min
The months with the most sunshine are June and July (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in August
Princeton, IL
- Average sunshine days in August: 15.4 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is June (11.8 days).
Average UV index in August
Princeton, IL
- Average UV index in August: 5
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in August
Princeton, IL
- Average cloud cover in August: 33
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in August
Princeton, IL
- Average visibility in August: 5mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).





