July weather forecast
O'Fallon, MO

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Weather in July

July represents the middle of summer and is, noticeably, the month with the highest day and night temperatures. As the heat peaks, days are now longer with approximately 14.6 hours of daylight. The number of sunshine hours, however, remains consistent with the previous month. The UV index maintains a steady value of 6 throughout, thereby making sun protection a necessity. Interestingly, while July might be sun-drenched, it also has its fair share of showers with rainfall distributed over 15.2 days.

Temperature

The warmest month is July, with an average high-temperature of 87.1°F (30.6°C) and an average low-temperature of 68.5°F (20.3°C).

Heat index

July's heat index is appraised at a sweltering 102.2°F (39°C). Implement more safety precautions, heat cramps and heat exhaustion may happen. Persistent activity could induce heatstroke.
From a standpoint of the heat index, values pertain to shaded conditions and mild breezes. With exposure to direct sunshine, the heat index could climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', measures the perceived warmth when incorporating the humidity present in the air. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant 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's vital to remain hydrated, particularly during prolonged physical activities.
Evaporating sweat is a key way the human body dispels excessive warmth, all thanks to the process of perspiration. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. Increasing body temperatures can be a precursor to dehydration if the body can't shed the extra heat.

Humidity

In July, the average relative humidity is 77%.

Rainfall

In O'Fallon, in July, it is raining for 15.2 days, with typically 2.48" (63mm) of accumulated precipitation. Throughout the year, in O'Fallon, there are 132.3 rainfall days, and 21.06" (535mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall.

Daylight

In July, the average length of the day is 14h and 34min.
On the first day of July, sunrise is at 5:41 am and sunset at 8:31 pm. On the last day of the month, sunrise is at 6:03 am and sunset at 8:14 pm CDT.

Sunshine

The average sunshine in July is 10.4h.

UV index

The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for average individuals.
Note: The maximum UV index of 6 during July translates into these guidelines:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.

Frequently asked questions

What is the hottest time of year?

July proves to be the warmest month in O'Fallon, Missouri, recording an average peak temperature of 87.1°F (30.6°C) and a minimum temperature of 68.5°F (20.3°C).

How hot is it in July?

In July, the average high-temperature and low-temperature are 87.1°F (30.6°C) and 68.5°F (20.3°C) respectively. The average heat index (a.k.a. 'apparent temperature', 'feels like'), which represents the influence of relative humidity on air temperature, in July is appraised at 102.2°F (39°C).

What is the average humidity in July?

In O'Fallon, the average relative humidity in July is 77%.

How much does it rain in July?

In O'Fallon, during July, the rain falls for 15.2 days and regularly aggregates up to 2.48" (63mm) of precipitation.

When it does not snow?

April through October are months without snowfall.

How many hours of daylight does O'Fallon have in July?

In July, the average day length is 14h and 34min.

When are sunrise and sunset in July?

On the first day of July, sunrise is at 5:41 am and sunset at 8:31 pm. On the last day of the month, sunrise is at 6:03 am and sunset at 8:14 pm CDT.

How many hours of sunshine does O'Fallon have in July?

The average sunshine duration in July is 10.4h.

What is the month with the highest UV index?

May through August, with an average maximum UV index of 6, are months with the highest UV index.

How high is the UV index in July?

In July, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in July
O'Fallon, MO

Average temperature in July - O
  • Average high temperature in July: 87.1°F

The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in July: 68.5°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).

Average pressure in July
O'Fallon, MO

Average pressure in July - O
  • Average pressure in July: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in July
O'Fallon, MO

Average wind speed in July - O
  • Average wind speed in July: 5.5mph

The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).

Average humidity in July
O'Fallon, MO

Average humidity in July - O
  • Average humidity in July: 77%

The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).

Average rainfall in July
O'Fallon, MO

Average rainfall in July - O
  • Average rainfall in July: 2.48"

The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.91").

Average rainfall days in July
O'Fallon, MO

Average rainfall days in July - O
  • Average rainfall days in July: 15.2 days

The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (6.8 days).

Average snowfall in July
O'Fallon, MO

Average snowfall in July - O
  • Average snowfall in July: 0"

The month with the highest snowfall is February (1.61").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in July
O'Fallon, MO

Average snowfall days in July - O
  • Average snowfall days in July: 0 days

The months with the highest number of snowfall days are January and February (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in July /
Average sunshine in July
O'Fallon, MO

Average daylight in July / Average sunshine in July - O
  • Average daylight in July: 14h and 4min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in July: 10h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 30min).
The months with the least sunshine are January and February (Average sunshine: 4h and 42min).

Average sunshine days in July
O'Fallon, MO

Average sunshine days in July - O
  • Average sunshine days in July: 12.6 days

The month with the most sunshine days is December (20.6 days).
The month with the least sunshine days is July (12.6 days).

Average UV index in July
O'Fallon, MO

Average UV index in July - O
  • Average UV index in July: 6

The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in July
O'Fallon, MO

Average cloud cover in July - O
  • Average cloud cover in July: 28

The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are June, July, August and September (Cloud cover 28).

Average visibility in July
O'Fallon, MO

Average visibility in July - O
  • Average visibility in July: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

O'Fallon, Missouri, USA

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