Contents
- Weather in August
- Frequently asked questions
- Average temperature in August
- Average pressure in August
- Average wind speed in August
- Average humidity in August
- Average rainfall in August
- Average rainfall days in August
- Average snowfall in August
- Average snowfall days in August
- Average daylight in August
- Average sunshine in August
- Average sunshine days in August
- Average UV index in August
- Average cloud cover in August
- Average visibility in August
Weather in August
Temperature
As Ottawa welcomes August, the average high-temperature records at a still moderately hot 79.3°F (26.3°C), marking an insignificant deviation from the prior month. During the month of August, the temperature falls to an average of 62.1°F (16.7°C).Humidity
The average relative humidity in August is 84%.Rainfall
In Ottawa, Illinois, in August, it is raining for 18.3 days, with typically 2.95" (75mm) of accumulated precipitation. Throughout the year, there are 166.3 rainfall days, and 35.35" (898mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In August, the average length of the day is 13h and 47min.On the first day of August, sunrise is at 5:51 am and sunset at 8:12 pm. On the last day of the month, sunrise is at 6:21 am and sunset at 7:29 pm CDT.
Sunshine
In August, the average sunshine is 9.7h.UV index
In Ottawa, the average daily maximum UV index in August is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The UV index of 5 during August leads to these advisories:
Ensure safety - Sun damage prevention is strongly urged. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. 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 are August temperatures?
What is the average humidity in August in Ottawa?
How many days does it rain in August?
When it does not snow?
What is the average length of the day in August?
What time are sunrise and sunset in August?
How long on average sun shines in August?
What is the UV index intensity in August?
Average temperature in August
Ottawa, IL
- Average high temperature in August: 79.3°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.1°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 (17.2°F).
Average pressure in August
Ottawa, IL
- Average pressure in August: 29.98"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in August
Ottawa, IL
- Average wind speed in August: 6.2mph
The windiest month (with the highest average wind speed) is April (10.2mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in August
Ottawa, IL
- Average humidity in August: 84%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in August
Ottawa, IL
- Average rainfall in August: 2.95"
The wettest month (with the highest rainfall) is May (5").
The driest month (with the least rainfall) is November (1.81").
Average rainfall days in August
Ottawa, IL
- Average rainfall days in August: 18.3 days
The month with the highest number of rainy days is July (19.9 days).
The month with the least rainy days is February (6.2 days).
Average snowfall in August
Ottawa, IL
- Average snowfall in August: 0"
The month with the highest snowfall is February (5.08").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Ottawa, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (12.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in August /
Average sunshine in August
Ottawa, IL
- Average daylight in August: 13h and 5min
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 4min
The month with the most sunshine is June (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in August
Ottawa, IL
- Average sunshine days in August: 9.9 days
The month with the most sunshine days is November (17 days).
The month with the least sunshine days is July (7.2 days).
Average UV index in August
Ottawa, IL
- Average UV index in August: 5
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in August
Ottawa, IL
- Average cloud cover in August: 33
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in August
Ottawa, IL
- Average visibility in August: 5mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
Ottawa, Illinois, USA
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