August weather forecastHarrisburg, IL
August
Weather in August
August in Harrisburg, Illinois witnesses the grandeur of a typical late summer. Temperatures remain comparably high, ranging from 66°F (18.9°C) to 85.6°F (29.8°C), albeit a slight dip from July. The hot and sunny weather forms the perfect backdrop for enjoying summer festivities and water sports, although the scorching sun might call for necessary precautions. Even though rainfall occurrences are relatively low, they do offer a refreshing change from the enduring heat. As August concludes, temperatures start to decline, marking the imminent arrival of Autumn.Temperature
August's arrival registers an average high-temperature of a warm 85.6°F (29.8°C), closely aligning with the temperature of the previous month. The average temperature during August nights dips to a refreshing 66°F (18.9°C).Heat index
In August, the heat index is evaluated at a very hot 96.8°F (36°C). Implement more preventive measures, heat cramps and heat exhaustion are probable. Heatstroke might result from extended activity.The heat index's values are generally associated with conditions in shade and light breezes. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'real feel' or 'feels like', arises from combining readings of air temperature and relative moisture content. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. One should be aware that direct sunshine can amplify the perceived temperature, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young ones are generally at greater risk than adults due to their limited sweating ability. In addition, their large skin surface relative to their small bodies and higher heat production from their activities add to their vulnerability.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. In circumstances of high air temperature and humidity (high heat index), the body's perspiration is restricted, heightening the feeling of warmth. Potential thermal conditions emerge as the body's heat gain outpaces its cooling mechanisms.
Humidity
In August, the average relative humidity is 76%.Rainfall
In August, the rain falls for 13.8 days. Throughout August, 2.52" (64mm) of precipitation is accumulated. In Harrisburg, during the entire year, the rain falls for 158.6 days and collects up to 36.02" (915mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In August, the average length of the day is 13h and 34min.On the first day of the month, sunrise is at 5:58 am and sunset at 8:02 pm. On the last day of August, sunrise is at 6:24 am and sunset at 7:24 pm CDT.
Sunshine
In Harrisburg, Illinois, the average sunshine in August is 10.3h.UV index
The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for average individuals.Note: A maximum high UV index of 6 in August translates into the following recommendations:
Employ safeguards and advocate sun safety protocols. Shielding against skin and eye damage is crucial. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Harrisburg, IL
- Average high temperature in August: 85.6°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in August: 66°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 (26.2°F).
Average pressure in August
Harrisburg, 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 (29.94"Hg).
Average wind speed in August
Harrisburg, IL
- Average wind speed in August: 5.8mph
The windiest months (with the highest average wind speed) are January and February (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in August
Harrisburg, IL
- Average humidity in August: 76%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in August
Harrisburg, IL
- Average rainfall in August: 2.52"
The wettest month (with the highest rainfall) is April (4.8").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in August
Harrisburg, IL
- Average rainfall days in August: 13.8 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is November (9.7 days).
Average snowfall in August
Harrisburg, IL
- Average snowfall in August: 0"
The month with the highest snowfall is January (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Harrisburg, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (5.3 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
Harrisburg, IL
- Average daylight in August: 13h and 36min
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 August: 10h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in August
Harrisburg, IL
- Average sunshine days in August: 15 days
The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is May (9.9 days).
Average UV index in August
Harrisburg, 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, February and December (UV index 2).
Average cloud cover in August
Harrisburg, IL
- Average cloud cover in August: 29
The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and September (Cloud cover 28).
Average visibility in August
Harrisburg, 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).
