July weather forecastWilliamsville, IL
July
Weather in July
July, like June, in Williamsville, Illinois, is a moderately hot summer month, with an average temperature fluctuating between 66°F (18.9°C) and 82.8°F (28.2°C).Temperature
Williamsville's temperature records reveal July as the warmest month, marked by average highs of 82.8°F (28.2°C) and lows of 66°F (18.9°C).Heat index
In July, the average heat index is calculated to be a tropical 91.4°F (33°C). Implement additional preventive actions, heat cramps and heat exhaustion are potential hazards. Heatstroke could follow prolonged activity.For clarity, heat index numbers account for light winds and areas under shade. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. Factors including metabolic differences, physical activity, and clothing are additional elements that influence the individual's temperature experience. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Children often fail to understand the importance of rest and rehydration. Thirst is a late manifestation of dehydration - hence, it is crucial to stay hydrated, especially during ongoing physical activities.
Humidity
With an average relative humidity of 84%, July is the most humid month.Rainfall
In Williamsville, during July, the rain falls for 14.6 days and regularly aggregates up to 1.69" (43mm) of precipitation. Throughout the year, there are 131.5 rainfall days, and 18.54" (471mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Williamsville.Daylight
In Williamsville, the average length of the day in July is 14h and 41min.On the first day of July, sunrise is at 5:33 am and sunset at 8:30 pm. On the last day of the month, sunrise is at 5:56 am and sunset at 8:12 pm CDT.
Sunshine
In July, the average sunshine is 10h.UV index
June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 6 during July translates into these guidelines:
Enforce precautions and stick to sun safety measures. Preservation from skin and eye damage is essential. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in July
Williamsville, IL
- Average high temperature in July: 82.8°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (33.1°F).
- Average low temperature in July: 66°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in July
Williamsville, IL
- Average pressure in July: 29.97"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in July
Williamsville, IL
- Average wind speed in July: 6.2mph
The windiest months (with the highest average wind speed) are January and April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in July
Williamsville, IL
- Average humidity in July: 84%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in July
Williamsville, IL
- Average rainfall in July: 1.69"
The wettest month (with the highest rainfall) is June (2.36").
The driest month (with the least rainfall) is December (0.83").
Average rainfall days in July
Williamsville, IL
- Average rainfall days in July: 14.6 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (5.7 days).
Average snowfall in July
Williamsville, IL
- Average snowfall in July: 0"
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in July
Williamsville, IL
- Average snowfall days in July: 0 days
The month with the highest number of snowfall days is January (8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in July /
Average sunshine in July
Williamsville, IL
- Average daylight in July: 14h and 42min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in July: 10h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in July
Williamsville, IL
- Average sunshine days in July: 13.1 days
The month with the most sunshine days is December (20.5 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in July
Williamsville, IL
- Average UV index in July: 6
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in July
Williamsville, IL
- Average cloud cover in July: 31
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are June, August and September (Cloud cover 30).
Average visibility in July
Williamsville, IL
- Average visibility in July: 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).
