St. Louis
Missouri, USA
Long-term weather forecast
Long-term weather forecast

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

Temperature

Julio is the warmest month in St. Louis, 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 Julio, the average heat index is estimated 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.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'felt air temperature', or 'real feel', is a measure of how hot it feels when the actual air humidity is factored in. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (wind, pregnancy, clothing). 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. 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.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. 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 Julio is 68%.

Rainfall

In St. Louis, Missouri, during 8.9 rainfall days, 4.11" (104.4mm) of precipitation is typically accumulated. In St. Louis, Missouri, during the entire year, the rain falls for 112.6 days and collects up to 40.96" (1040.3mm) of precipitation.

Snowfall

Mayo through Octubre are months without snowfall in St. Louis.

Daylight

In Julio, the average length of the day in St. Louis, Missouri, is 14.6h.

Sunshine

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

UV index

Months with the highest UV index in St. Louis are Junio through Agosto, with an average maximum UV index of 9. A UV Index reading of 8 to 10 represents a very high threat to health from unsafe exposure to the UV radiation for average individuals.
Note: The daily maximum UV index of 9 interpret into the following advice:
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 warmest month in St. Louis?

The warmest month in St. Louis is Julio, 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 Julio in St. Louis?

In St. Louis, Missouri, in Julio, the average high-temperature is 89.1°F (31.7°C), and the average low-temperature is 71.1°F (21.7°C). In Julio, the average heat index (a.k.a. 'real feel', 'apparent temperature'), that represents influence of the relative humidity to air temperaure, is evaluated at 102°F (38.9°C).

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

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

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

In St. Louis, Missouri, in Julio, it is raining for 8.9 days, with typically 4.11" (104.4mm) of accumulated precipitation.

When it does not snow in St. Louis?

In St. Louis snow does not fall in Mayo through Octubre.

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

The average length of the day in Julio is 14.6h.

What month has the most sunshine in St. Louis?

With an average of 10h of sunshine, Julio has the most sunshine of the year.

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

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

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

Junio through Agosto, with an average maximum UV index of 9, are months with the highest UV index in St. Louis, Missouri.

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

In St. Louis, Missouri, the average daily maximum UV index in Julio is 9. A UV Index value of 8 to 10 symbolizes a very high hazard to health from unprotected exposure to the UV radiation.
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).

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%).

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 lowest rainfall) is February (2.2").

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 lowest number of rainy days is September (7.4 days).

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

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

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).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average daylight in July / Average sunshine in July - St. Louis, MO
  • Average daylight in July: 14.6h

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

  • Average sunshine in July: 10h

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

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