June weather forecast and climate
St. Louis, MO

A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
June, the first month of the summer, in St. Louis, is still a warm month, with temperature in the range of an average high of 85.1°F (29.5°C) and an average low of 66.7°F (19.3°C).

Temperature

In June, the average high-temperature in St. Louis, Missouri, marginally rises, from 76.3°F (24.6°C) in May, to a still warm 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 91.8°F (33.2°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. With the 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 'feels like', 'felt air temperature', 'apparent temperature', or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, wind, metabolic differences), and activity. 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 particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

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

Rainfall

In St. Louis, during 10 rainfall days, 4.28" (108.7mm) of precipitation is typically accumulated. In St. Louis, during the entire year, the rain falls for 112.6 days and collects up to 40.96" (1040.3mm) of precipitation.

Snowfall

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

Daylight

June has the longest days of the year in St. Louis, Missouri, with an average of 14.8h of daylight.

Sunshine

In St. Louis, Missouri, the average sunshine is 9.7h.

UV index

Months with the highest UV index in St. Louis are June through August, with an average maximum UV index of 9. A UV Index reading of 8 to 10 represents a very high threat to health from the exposure to the Sun's UV rays for the average person.
Note: In June, the average maximum UV index of 9 translate into the following recommendations:
Take special precautions, as unprotected skin can be damaged and can burn quickly. 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. 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.

What is the temperature in June in St. Louis?

The average high-temperature, in June, in St. Louis, Missouri, is 85.1°F (29.5°C), while the average low-temperature is 66.7°F (19.3°C). In June, the average heat index (a.k.a. 'real feel', 'felt air temperature'), that combines air temperature and relative humidity, is appraised at 91.8°F (33.2°C).

What is the average humidity in June in St. Louis?

In June, the average relative humidity is 67.1%.

How much does it rain in St. Louis in June?

In June, the rain falls for 10 days. Throughout June, 4.28" (108.7mm) of precipitation is accumulated.

When it does not snow in St. Louis?

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

When are the longest days in St. Louis?

The month with the longest days in St. Louis, Missouri, is June, with an average of 14.8h of daylight.

How many hours of daylight does St. Louis have in June?

In June, the average length of the day is 14.8h.

How long on average sun shines in June in St. Louis?

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

When is the highest UV index in St. Louis?

June through August, with an average maximum UV index of 9, are months with the highest UV index in St. Louis.

How high is the UV index in June in St. Louis?

The average daily maximum UV index in June is 9. A UV Index value of 8 to 10 symbolizes a very high health threat from unsafe exposure to the Sun's UV rays.
Average temperature in June - St. Louis, MO
  • Average high temperature in June: 29.5°C

The warmest month (with the highest average high temperature) is July (31.7°C).
The month with the lowest average high temperature is January (4.4°C).

  • Average low temperature in June: 19.3°C

The month with the highest average low temperature is July (21.7°C).
The coldest month (with the lowest average low temperature) is January (-4.6°C).

Average humidity in June - St. Louis, MO
  • Average humidity in June: 67.1%

The month with the highest relative humidity is December (75.8%).
The month with the lowest relative humidity is April (63.5%).

Average rainfall in June - St. Louis, MO
  • Average rainfall in June: 108.7mm

The wettest month (with the highest rainfall) is May (119.9mm).
The driest month (with the least rainfall) is February (56.9mm).

Average rainfall days in June - St. Louis, MO
  • Average rainfall days in June: 10 days

The month with the highest number of rainy days is May (11.9 days).
The month with the least rainy days is September (7.4 days).

Average snowfall in June - St. Louis, MO
  • Average snowfall in June: 0mm

The month with the highest snowfall is January (142.2mm).
Months with the least snowfall are May, June, July, August, September and October (0mm).

Average snowfall days in June - St. Louis, MO
  • Average snowfall days in June: 0 days

The month with the highest number of snowfall days is January (4.7 days).
Months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in June / Average sunshine in June - St. Louis, MO
  • Average daylight in June: 14.8h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in June: 9.7h

The month with the most sunshine is July (Average sunshine: 10h).
The month with the least sunshine is December (Average sunshine: 4.2h).

Average UV index in June - St. Louis, MO
  • Average UV index in June: 9

Months with the highest UV index are June, July and August (UV index 9).
Months with the lowest UV index are January and December (UV index 2).