June weather forecast
St. Louis, MO

St. Louis experiences the official advent of summer in June. Temperatures continue their upward incline, creating warm, typically summery conditions. Average daytime temperatures climb to a pleasant 66.8°F (19.3°C), perfect for enjoying an outdoor picnic or a leisurely day boating on the Mississippi. The sunny days of June yield high UV indexes, encouraging residents to take necessary sun precautions. Intermittent spells of rainfall serve as a refreshing break from the summer heat.

Temperature

Observing a slight rise in June, the average high-temperature in St. Louis shifts from May's warm 76.3°F (24.6°C) to a still moderately hot 85.1°F (29.5°C). St. Louis experiences a consistent average temperature of 66.7°F (19.3°C) throughout the nights in June.

Heat index

The heat index value for June is evaluated at a tropical 91.4°F (33°C). Greater safety measures are needed, risk of heat exhaustion and heat cramps is high. Continuous activity might trigger heatstroke.
The metrics for the heat index are tailored for both shady environments and light winds. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. 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 hold particular importance for children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.

Humidity

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

Rainfall

In June, in St. Louis, the rain falls for 10 days. Throughout June, 4.29" (109mm) of precipitation is accumulated. Throughout the year, in St. Louis, there are 112.6 rainfall days, and 40.94" (1040mm) of precipitation is accumulated.

Snowfall

In St. Louis, snow does not fall in May through October.

Daylight

The month with the longest days in St. Louis is June, with an average of 14h and 48min of daylight.
On the first day of the month, sunrise is at 5:37 am and sunset at 8:19 pm. On the last day of June, in St. Louis, sunrise is at 5:39 am and sunset at 8:29 pm CDT.

Sunshine

The average sunshine in June in St. Louis, Missouri, 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 health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: The daily high UV index of 9 in June translates into this advice:
Remember to safeguard yourself. Rapid damage can occur to skin and eyes without protection. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. After a swim or outdoor exercise, one should liberally reapply broad-spectrum sunscreen with a sun protection factor of 30 or higher.