July weather forecast
St. Louis, MO

A beautiful twilight over the Gateway Arch in St. Louis, Missouri
A beautiful twilight over the Gateway Arch in St. Louis, Missouri

Weather in July

July in St. Louis is a tropical summer month, with an average temperature fluctuating between 71.1°F (21.7°C) and 89.1°F (31.7°C).

Temperature

The warmest month in St. Louis, Missouri, is July, with an average high-temperature of 89.1°F (31.7°C) and an average low-temperature of 71.1°F (21.7°C).

Heat index

In July, the average heat index is evaluated at a sweltering 102°F (38.9°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. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'apparent temperature', 'felt air temperature', or 'feels like', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, clothing, wind), and activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. 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.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In St. Louis, the average relative humidity in July is 68%.

Rainfall

In St. Louis, Missouri, it is raining for 8.9 days, with typically 4.11" (104.4mm) of accumulated precipitation. Throughout the year, in St. Louis, Missouri, there are 112.6 rainfall days, and 40.96" (1040.3mm) of precipitation is accumulated.

Snowfall

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

Daylight

In St. Louis, the average length of the day in July is 14h and 33min.
On the first day of July in St. Louis, sunrise is at 5:40 am and sunset at 8:29 pm. On the last day of the month, sunrise is at 6:01 am and sunset at 8:12 pm CDT.

Sunshine

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

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 hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily maximum UV index of 9 in July interpret into the following advice:
Take special precautions, as unprotected eyes and skin can be burned and damaged 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. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. 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.
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FAQ

What is the warmest month in St. Louis?

The warmest month is July, with an average high-temperature of 89.1°F (31.7°C) and an average low-temperature of 71.1°F (21.7°C).

What is the temperature in July in St. Louis?

The average high-temperature, in July, in St. Louis, is 89.1°F (31.7°C), while the average low-temperature is 71.1°F (21.7°C). In July, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines air temperature and relative humidity, is evaluated at 102°F (38.9°C).

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

In July, the average relative humidity is 68%.

How many days does it rain in July in St. Louis?

In St. Louis, Missouri, in July, during 8.9 rainfall days, 4.11" (104.4mm) of precipitation is typically accumulated.

When it does not snow in St. Louis?

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

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

In St. Louis, Missouri, the average day length in July is 14h and 33min.

What time are sunrise and sunset in July in St. Louis?

In July, on the first day of the month, sunrise is at 5:40 am and sunset at 8:29 pm. On the last day of the month, in St. Louis, Missouri, sunrise is at 6:01 am and sunset at 8:12 pm CDT.

What month has the most sunshine in St. Louis?

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

How many hours of sunshine does St. Louis have in July?

The average sunshine duration in July in St. Louis, Missouri, is 10h.

What is the month with the highest UV index in St. Louis?

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

What is the UV index intensity in July in St. Louis?

In St. Louis, Missouri, the average daily maximum UV index in July is 9. A UV Index value of 8 to 10 symbolizes a very high health vulnerability from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average UV index

Average temperature in July
St. Louis, MO

Average temperature in July - St. Louis, MO
  • Average high temperature in July: 89.1°F

The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is January (39.9°F).

  • Average low temperature in July: 71°F

The month with the highest average low temperature is July (71°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).

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Average humidity in July
St. Louis, MO

Average humidity in July - St. Louis, MO
  • Average humidity in July: 68%

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

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Average rainfall in July
St. Louis, MO

Average rainfall in July - St. Louis, MO
  • Average rainfall in July: 4.1"

The wettest month (with the highest rainfall) is May (4.7").
The driest month (with the least rainfall) is February (2.2").

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Average rainfall days in July
St. Louis, MO

Average rainfall days in July - St. Louis, MO
  • Average rainfall days in July: 8.9 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).

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Average snowfall in July
St. Louis, MO

Average snowfall in July - St. Louis, MO
  • Average snowfall in July: 0"

The month with the highest snowfall is January (5.6").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in July
St. Louis, MO

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

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

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Average daylight in July /
Average sunshine in July
St. Louis, MO

Average daylight in July / Average sunshine in July - St. Louis, MO
  • Average daylight in July: 14h and 33min

The month with the longest days is June (Average daylight: 14h and 49min).
The month with the shortest days is December (Average daylight: 9h and 31min).

  • Average sunshine in July: 10h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).

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Average UV index in July
St. Louis, MO

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

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

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