July weather forecast
Marion, IL

July is the peak of summer in Marion, holding the record for the highest average temperatures of the year. The city witnesses the warmest conditions with average high temperatures achieving 87.4°F (30.8°C) and lows mildly reducing to 68.5°F (20.3°C). Despite the high temperatures, July competes with June in terms of maximum sunshine duration. The increase in humidity, paired with high temperatures, can cause muggy conditions. The progress towards August does not bring significant changes, but a slight dip in temperature with a reduced amount of sunlight can be witnessed.

Temperature

Temperature readings reach their annual highs in July, averaging 87.4°F (30.8°C) and a minimum average of 68.5°F (20.3°C).

Heat index

In July, the heat index is estimated at a fiery hot 102.2°F (39°C). Undertake extra safety actions, heat cramps and heat exhaustion are expected. Heatstroke may result from lengthy activity.
Be aware that heat index ratings are designed for shaded locations and minor breezes. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', shows a temperature sensation when both heat and moisture conditions are combined. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children often miss understanding the importance of rest and rehydration. Thirst usually appears late during dehydration - therefore, maintaining hydration, particularly during long physical activities, is essential.
The physiological response of the human body to excess warmth is to perspire, thereby cooling itself through sweat evaporation. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

In Marion, the average relative humidity in July is 77%.

Rainfall

In July, the rain falls for 15.3 days. Throughout July, 2.09" (53mm) of precipitation is accumulated. Throughout the year, there are 137.6 rainfall days, and 23.03" (585mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In Marion, the average length of the day in July is 14h and 28min.
On the first day of the month, sunrise is at 5:38 am and sunset at 8:21 pm. On the last day of July, sunrise is at 5:59 am and sunset at 8:05 pm CDT.

Sunshine

The months with the most sunshine are June and July, with an average of 10.5h of sunshine.

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 hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: In July, a daily UV index of 6 turns into the following recommendations:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.