July weather forecast
Williamson, IL

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Weather in July

July, like June, in Williamson, Illinois, is another warm summer month, with an average temperature fluctuating between 67.5°F (19.7°C) and 84.2°F (29°C).

Temperature

In Williamson, July is the warmest month, with temperatures averaging a high of 84.2°F (29°C) and a low of 67.5°F (19.7°C).

Heat index

For most parts of July, the heat index is computed to be a torrid 95°F (35°C). Special measures are necessary to avoid heat cramps and heat exhaustion. Persistent activity could result in heatstroke.
Understanding the heat index involves considering values for shaded locales with light wind. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Children often fail to recognize the requirement to rest and rehydrate. Thirst, being a late symptom of dehydration, underlines the importance of maintaining hydration, especially during ongoing physical activities.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. In circumstances of high air temperature and humidity (high heat index), the body's perspiration is restricted, heightening the feeling of warmth. With body temperatures on the rise, inefficient heat shedding can lead to dehydration and its associated complications.

Humidity

July is the most humid month in Williamson, with an average relative humidity of 81%.

Rainfall

In Williamson, in July, it is raining for 14 days, with typically 1.5" (38mm) of accumulated precipitation. In Williamson, during the entire year, the rain falls for 121.4 days and collects up to 14.72" (374mm) of precipitation.

Snowfall

In Williamson, snow does not fall in April through October.

Daylight

In Williamson, the average length of the day in July is 14h and 35min.
On the first day of July, sunrise is at 5:37 am and sunset at 8:28 pm. On the last day of the month, sunrise is at 5:59 am and sunset at 8:11 pm CDT.

Sunshine

The months with the most sunshine are June and July, with an average of 10.3h of sunshine.

UV index

The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 6 during July translates into the following directions:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.

Frequently asked questions

What is the warmest month?

July, marked by an average high-temperature of 84.2°F (29°C) and a low-temperature of 67.5°F (19.7°C), is the warmest month.

How hot is July?

Williamson in July has an average high-temperature of 84.2°F (29°C) and an average low-temperature of 67.5°F (19.7°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines relative humidity and air temperature, in July is computed to be 95°F (35°C).

What is the most humid month?

July is the most humid month, with an average relative humidity of 81%.

What is the average humidity in July?

The average relative humidity in July in Williamson is 81%.

How many days does it rain in July in Williamson?

In Williamson, in July, it is raining for 14 days, with typically 1.5" (38mm) of accumulated precipitation.

When it does not snow in Williamson?

April through October are months without snowfall.

What is the average length of the day in July?

In July, the average day length is 14h and 35min.

When is the sunrise / sunset in July?

On the first day of July, sunrise is at 5:37 am and sunset at 8:28 pm. On the last day of the month, sunrise is at 5:59 am and sunset at 8:11 pm CDT.

What is the month with the most sunshine in Williamson?

The months with the most sunshine are June and July, with an average of 10.3h of sunshine.

How long on average sun shines in July?

In July, the average sunshine duration is 10.3h.

What is the month with the highest UV index?

June through August, with an average maximum UV index of 6, are months with the highest UV index in Williamson.

How high is the UV index in July?

The average daily maximum UV index in July is 6. A UV Index value of 6 to 7 symbolizes a high hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in July
Williamson, IL

Average temperature in July - Williamson, IL
  • Average high temperature in July: 84.2°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).

  • Average low temperature in July: 67.5°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).

Average pressure in July
Williamson, IL

Average pressure in July - Williamson, IL
  • Average pressure in July: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in July
Williamson, IL

Average wind speed in July - Williamson, IL
  • Average wind speed in July: 5.8mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

Average humidity in July
Williamson, IL

Average humidity in July - Williamson, IL
  • Average humidity in July: 81%

The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).

Average rainfall in July
Williamson, IL

Average rainfall in July - Williamson, IL
  • Average rainfall in July: 1.5"

The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").

Average rainfall days in July
Williamson, IL

Average rainfall days in July - Williamson, IL
  • Average rainfall days in July: 14 days

The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).

Average snowfall in July
Williamson, IL

Average snowfall in July - Williamson, IL
  • Average snowfall in July: 0"

The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in July
Williamson, IL

Average snowfall days in July - Williamson, IL
  • Average snowfall days in July: 0 days

The month with the highest number of snowfall days is January (6.3 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
Williamson, IL

Average daylight in July / Average sunshine in July - Williamson, IL
  • Average daylight in July: 14h and 4min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in July: 10h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in July
Williamson, IL

Average sunshine days in July - Williamson, IL
  • Average sunshine days in July: 12.5 days

The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).

Average UV index in July
Williamson, IL

Average UV index in July - Williamson, 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
Williamson, IL

Average cloud cover in July - Williamson, IL
  • Average cloud cover in July: 29

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).

Average visibility in July
Williamson, IL

Average visibility in July - Williamson, IL
  • Average visibility in July: 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).

Williamson, Illinois, USA

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