August weather forecastMount Vernon, IL
August
Weather in August
August, the last month of the summer in Mount Vernon, is also a moderately hot month, with an average temperature fluctuating between 65.8°F (18.8°C) and 84°F (28.9°C).Temperature
The commencement of August brings an average high-temperature of a still warm 84°F (28.9°C), marking an inconsequential divergence from July. August nights cool down to an average low-temperature of 65.8°F (18.8°C).Heat index
August's average heat index is evaluated at a hot 93.2°F (34°C). Implement enhanced safety actions, heat cramps and heat exhaustion could occur. Sustained activity might result in heatstroke.It is important to note that the heat index values are for shaded areas and light wind scenarios. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', embodies the combination of air temperature and moisture content to illustrate perceived heat. Additional elements encompassing metabolic differences, the degree of physical activity, and attire can impact the individual's perception of temperature. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
The average relative humidity in August in Mount Vernon is 78%.Rainfall
In August, in Mount Vernon, the rain falls for 13.4 days. Throughout August, 2.36" (60mm) of precipitation is accumulated. In Mount Vernon, during the entire year, the rain falls for 145.8 days and collects up to 29.13" (740mm) of precipitation.Snowfall
In Mount Vernon, snow does not fall in May through October.Daylight
In Mount Vernon, Illinois, the average length of the day in August is 13h and 37min.On the first day of August in Mount Vernon, sunrise is at 5:58 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 6:24 am and sunset at 7:26 pm CDT.
Sunshine
The average sunshine in August in Mount Vernon is 10.2h.UV index
The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for the average person.Note: A daily high UV index of 6 in August leads to these guidelines:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Mount Vernon, IL
- Average high temperature in August: 84°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in August: 65.8°F
The month with the highest average low temperature is July (67.8°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in August
Mount Vernon, IL
- Average pressure in August: 29.98"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 August
Mount Vernon, IL
- Average wind speed in August: 5.9mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.9mph).
Average humidity in August
Mount Vernon, IL
- Average humidity in August: 78%
The month with the highest relative humidity is May (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in August
Mount Vernon, IL
- Average rainfall in August: 2.36"
The wettest month (with the highest rainfall) is April (3.78").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in August
Mount Vernon, IL
- Average rainfall days in August: 13.4 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in August
Mount Vernon, IL
- Average snowfall in August: 0"
The month with the highest snowfall is February (1.73").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in August
Mount Vernon, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (4.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in August /
Average sunshine in August
Mount Vernon, IL
- Average daylight in August: 13h and 36min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in August: 10h and 12min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in August
Mount Vernon, IL
- Average sunshine days in August: 15.6 days
The month with the most sunshine days is October (20.3 days).
The month with the least sunshine days is May (11.3 days).
Average UV index in August
Mount Vernon, IL
- Average UV index in August: 6
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, November and December (UV index 2).
Average cloud cover in August
Mount Vernon, IL
- Average cloud cover in August: 28
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in August
Mount Vernon, IL
- Average visibility in August: 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).
