July weather forecast
St. Louis, MO

July is the warmest month of the year in St. Louis. High temperatures reach their zenith in this month, registering an all-year high of 71°F (21.7°C). Residents and tourists alike eagerly anticipate the quintessential southern summer, filled with sunny days and warm nights. The resurgence of humidity necessitates regular hydration. Yet, despite the humidity, July proves to be a popular month for outdoor concerts and music festivals in the city.

Temperature

The month of July, characterized by an average high of 89.1°F (31.7°C) and a low of 71.1°F (21.7°C), is recognized as the warmest in St. Louis.

Heat index

For July, the heat index is evaluated at a torrid 102.2°F (39°C). Implement additional safety measures to avoid heat cramps and heat exhaustion. Persistent activity might trigger heatstroke.
Heat index specifics point out values are for conditions of shade and a slight breeze. Heat index values may rise by up to 15 Fahrenheit (8 Celsius) degrees when exposed to direct sunlight.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Keep it in mind, direct sunlight can augment the heat you experience, possibly pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
When the body gets too warm, it perspires, leading to sweat evaporation which cools it down. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

The average relative humidity in July in St. Louis is 68%.

Rainfall

In St. Louis, during July, the rain falls for 8.9 days and regularly aggregates up to 4.09" (104mm) of precipitation. In St. Louis, during the entire year, the rain falls for 112.6 days and collects up to 40.94" (1040mm) of precipitation.

Snowfall

May through October are months without snowfall in St. Louis.

Daylight

The average length of the day in July in St. Louis is 14h and 33min.
On the first day of the month, sunrise is at 5:40 am and sunset at 8:29 pm. On the last day of July, in St. Louis, sunrise is at 6:02 am and sunset at 8:12 pm CDT.

Sunshine

July has the most sunshine of the year in St. Louis, with an average of 10h of sunshine.

UV index

June through August, with an average maximum UV index of 9, are months with the highest UV index in St. Louis. A UV Index of 8 to 10 symbolizes a very high health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In July, the UV index of 9 transforms into the following advice:
Skin and eyes are vulnerable without protection. Ensure you always take precautions. Seek shade and limit direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Keep in mind that shade structures like parasols or canopies do not offer complete sun protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Apply liberally and reapply a broad-spectrum sunscreen of SPF 30+ every two hours, and promptly after any outdoor workout or a swim.