June weather forecast
O'Fallon, MO

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Weather in June

By June, summer is unmistakably in full swing, bringing with it the delight of sun-soaked days. The transition from May is notable with a climb in day and night temperatures. A definite decrease in wind speed as we move into June ensures that no gusty winds interrupt a perfect outing. However, despite strong sun rays, the UV index stays constant at 6, reminding residents to keep their sunscreen handy. What is remarkable is the drop in snowfall, with absolutely no incidence recorded, indicating a clean break from the cooler months.

Temperature

The shift from May to June in O'Fallon is marked by an increase in the average high-temperature, moving from 74.5°F (23.6°C) to a still moderately hot 83.8°F (28.8°C). O'Fallon records an average low of 66.2°F (19°C) throughout the nights in June.

Heat index

For most parts of June, the heat index is evaluated at a tropical 93.2°F (34°C). Exercise more precautions, heat cramps and heat exhaustion are potential risks. Continuous activity could precipitate heatstroke.
It is crucial to understand that heat index figures are for shade and gentle wind conditions. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', integrates the air's temperature and its humidity to showcase the felt temperature by people. A person's impression of weather can be shaped by many aspects, among them metabolic variations, pregnancy, and levels of physical activity. Direct sun rays have a notable impact on perceived temperature, which can raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.

Humidity

In June, the average relative humidity is 77%.

Rainfall

In O'Fallon, in June, it is raining for 14.4 days, with typically 2.13" (54mm) of accumulated precipitation. In O'Fallon, during the entire year, the rain falls for 132.3 days and collects up to 21.06" (535mm) of precipitation.

Snowfall

In O'Fallon, Missouri, snow does not fall in April through October.

Daylight

June has the longest days of the year in O'Fallon, with an average of 14h and 48min of daylight.
On the first day of the month, sunrise is at 5:39 am and sunset at 8:22 pm. On the last day of June, in O'Fallon, sunrise is at 5:41 am and sunset at 8:31 pm CDT.

Sunshine

The month with the most sunshine in O'Fallon is June, with an average of 10.5h of sunshine.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the average person.
Note: The daily high UV index of 6 in June translates into this advice:
Inhibit overexposure. Warding off sun damage is of utmost importance. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. 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.
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Frequently asked questions

How hot does it get in O'Fallon in June?

The high-temperature, in June, in O'Fallon, records 83.8°F (28.8°C), while the low-temperature is 66.2°F (19°C). The average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, in June is evaluated at 93.2°F (34°C).

What is the average humidity in June in O'Fallon?

The average relative humidity in June in O'Fallon, Missouri, is 77%.

How many days does it rain in June in O'Fallon?

In O'Fallon, Missouri, in June, during 14.4 rainfall days, 2.13" (54mm) of precipitation is typically accumulated.

When it does not snow in O'Fallon?

In O'Fallon, Missouri, snow does not fall in April through October.

When are the longest days in O'Fallon?

June has the longest days of the year in O'Fallon, with an average of 14h and 48min of daylight.

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

In O'Fallon, Missouri, the average day length in June is 14h and 50min.

When are sunrise and sunset in June in O'Fallon?

In June, on the first day of the month, sunrise is at 5:39 am and sunset at 8:22 pm. On the last day of the month, in O'Fallon, Missouri, sunrise is at 5:41 am and sunset at 8:31 pm CDT.

What month has the most sunshine in O'Fallon?

June has the most sunshine of the year in O'Fallon, with an average of 10.5h of sunshine.

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

The average sunshine duration in June is 10.5h.

When is the highest UV index in O'Fallon?

The months with the highest UV index in O'Fallon are May through August, with an average maximum UV index of 6.

What is the UV index intensity in June in O'Fallon?

The average daily maximum UV index in June is 6. A UV Index reading of 6 to 7 represents a high health threat 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 June
O'Fallon, MO

Average temperature in June - O
  • Average high temperature in June: 83.8°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 June: 66.2°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).

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Average pressure in June
O'Fallon, MO

Average pressure in June - O
  • Average pressure in June: 29.92"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).

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Average wind speed in June
O'Fallon, MO

Average wind speed in June - O
  • Average wind speed in June: 6.4mph

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).

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Average humidity in June
O'Fallon, MO

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

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

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Average rainfall in June
O'Fallon, MO

Average rainfall in June - O
  • Average rainfall in June: 2.13"

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

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Average rainfall days in June
O'Fallon, MO

Average rainfall days in June - O
  • Average rainfall days in June: 14.4 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).

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Average snowfall in June
O'Fallon, MO

Average snowfall in June - O
  • Average snowfall in June: 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").

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Average snowfall days in June
O'Fallon, MO

Average snowfall days in June - O
  • Average snowfall days in June: 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).

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

Average daylight in June / Average sunshine in June - O
  • Average daylight in June: 14h and 5min

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 June: 10h and 3min

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).

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Average sunshine days in June
O'Fallon, MO

Average sunshine days in June - O
  • Average sunshine days in June: 13 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).

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Average UV index in June
O'Fallon, MO

Average UV index in June - O
  • Average UV index in June: 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).

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Average cloud cover in June
O'Fallon, MO

Average cloud cover in June - O
  • Average cloud cover in June: 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).

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Average visibility in June
O'Fallon, MO

Average visibility in June - O
  • Average visibility in June: 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).

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O'Fallon, Missouri, USA

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