June weather forecast
St. Louis, MO

June, the first month of the summer in St. Louis, is also a moderately hot month, with temperature in the range of an average low of 66.7°F (19.3°C) and an average high of 85.1°F (29.5°C).

Temperature

In June, the average high-temperature in St. Louis slightly increases from a warm 76.3°F (24.6°C) in May to a still moderately hot 85.1°F (29.5°C). In June, in St. Louis, the average low-temperature is 66.7°F (19.3°C).

Heat index

In June, the average heat index is estimated at a hot 91.4°F (33°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'feels like', 'real feel', or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. Additional factors like differences in body mass, height, and shape, metabolic differences, wind, and activity influence one's weather impression. 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 are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

The average relative humidity in June in St. Louis is 67.1%.

Rainfall

In St. Louis, Missouri, in June, during 10 rainfall days, 4.29" (109mm) of precipitation is typically accumulated. In St. Louis, Missouri, 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 month with the longest days in St. Louis is June, with an average of 14h and 49min of daylight.
On the first day of June in St. Louis, sunrise is at 5:37 am and sunset at 8:19 pm. On the last day of the month, sunrise is at 5:39 am and sunset at 8:29 pm CDT.

Sunshine

In June, the average sunshine in St. Louis is 9.7h.

UV index

The months with the highest UV index in St. Louis are June through August, with an average maximum UV index of 9. A UV Index estimate of 8 to 10 represents a very high threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: The average daily UV index of 9 in June transform into the following instructions:
Take extra precautions. Protection against sun damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise.