Contents
- Weather in July
- Frequently asked questions
- Average temperature in July
- Average pressure in July
- Average wind speed in July
- Average humidity in July
- Average rainfall in July
- Average rainfall days in July
- Average snowfall in July
- Average snowfall days in July
- Average daylight in July
- Average sunshine in July
- Average sunshine days in July
- Average UV index in July
- Average cloud cover in July
- Average visibility in July
Weather in July
Temperature
Saint Johns's July weather, marked by an average high temperature of 87.3°F (30.7°C) and an average low temperature of 68.7°F (20.4°C), is the warmest in the year.Heat index
July's average heat index is calculated to be a sweltering 102.2°F (39°C). Special measures are necessary to avoid heat cramps and heat exhaustion. Persistent activity could result in heatstroke.Research indicates the heat index considers values in shaded locales and with light winds. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'feels like' or 'felt air temperature', melds the effects of warmth and moisture to generate a feeling of heat. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Kids are usually in more danger than grown-ups as they tend to sweat less. Plus, their bigger skin surface in relation to their small frames and increased heat generation due to their activity level make them more susceptible.
To offset high temperatures, the human body releases sweat which, upon evaporation, cools it down. In situations of high air temperature combined with high humidity (significant heat index), the body's ability to perspire is reduced, heightening the sense of warmth. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.
Humidity
The average relative humidity in July is 77%.Rainfall
In Saint Johns, during July, the rain falls for 16.3 days and regularly aggregates up to 3.07" (78mm) of precipitation. In Saint Johns, Illinois, during the entire year, the rain falls for 147.6 days and collects up to 29.17" (741mm) of precipitation.Snowfall
In Saint Johns, snow does not fall in May through October.Daylight
In July, the average length of the day is 14h and 30min.On the first day of July, sunrise is at 5:38 am and sunset at 8:23 pm. On the last day of the month, sunrise is at 5:59 am and sunset at 8:06 pm CDT.
Sunshine
With an average of 10.5h of sunshine, July has the most sunshine of the year.UV index
The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 6 in July interprets into the following advice:
Take precautions against overexposure. Protection against sun damage is needed. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the warmest months?
How hot does it get in July?
What is the average humidity in July?
How many days does it rain in July?
When it does not snow?
What is the average length of the day in July?
What time are sunrise and sunset in July?
What month has the most sunshine?
How many hours of sunshine does Saint Johns have in July?
What is the month with the highest UV index?
How high is the UV index in July in Saint Johns?
Average temperature in July
Saint Johns, IL
- Average high temperature in July: 87.3°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 (38.8°F).
- Average low temperature in July: 68.7°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in July
Saint Johns, IL
- Average pressure in July: 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 July
Saint Johns, IL
- Average wind speed in July: 5.8mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in July
Saint Johns, IL
- Average humidity in July: 77%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in July
Saint Johns, IL
- Average rainfall in July: 3.07"
The wettest month (with the highest rainfall) is April (3.58").
The driest month (with the least rainfall) is January (1.5").
Average rainfall days in July
Saint Johns, IL
- Average rainfall days in July: 16.3 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is December (8.2 days).
Average snowfall in July
Saint Johns, IL
- Average snowfall in July: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in July
Saint Johns, IL
- Average snowfall days in July: 0 days
The month with the highest number of snowfall days is January (5.4 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
Saint Johns, IL
- Average daylight in July: 14h and 3min
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 July: 10h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in July
Saint Johns, IL
- Average sunshine days in July: 12 days
The months with the most sunshine days are October and November (19.5 days).
The month with the least sunshine days is May (11.4 days).
Average UV index in July
Saint Johns, 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
Saint Johns, IL
- Average cloud cover in July: 29
The months with the most cloud cover are January and February (Cloud cover 50).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in July
Saint Johns, 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).
Saint Johns, Illinois, USA
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