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March Weather in O'Fallon, United States

Last updated: June 24, 2025

In March, the average temperature in O'Fallon, United States hovers around 8°C (47°F), with a notable temperature range that can swing from a chilly -17°C (2°F) to a surprisingly warm 28°C (83°F). Expect 128 mm (5.0 in) of precipitation, spread over approximately 11 days, contributing to the region's high average humidity of 80%. Stay prepared for a mix of weather conditions!

March Temperature in O'Fallon

In March in O'Fallon, the average temperature is 8°C (47°F). Maximums can reach 28°C (83°F) and minimums can be as low as -17°C (2°F). It’s advisable to pack layers to accommodate the wide range of temperatures while traveling.

March Weather in O'Fallon: Daily Temperature Highs, Lows, and Averages

The chart illustrates March temperature patterns in O'Fallon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In O'Fallon, March typically has an average temperature of 8°C (47°F), with highs reaching up to 28°C (83°F) and lows dropping to around -17°C (2°F).
JanFebMarAprMayJunJulAugSepOctNovDec323546556776797672594439
Data source: Temperature data for O'Fallon generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

March Precipitation in O'Fallon

In O'Fallon in March, the total precipitation amount is 128 mm (5.0 in) spread over 11 days.

March Precipitation Trends in O'Fallon

The chart displays monthly precipitation patterns in O'Fallon, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In O'Fallon, March typically receives around 128 mm (5.0 inches) of precipitation spread over approximately 11 days.
JanFebMarAprMayJunJulAugSepOctNovDec72781281211458497139561106852
Data source: Precipitation data for March generated using information from the Copernicus Climate Change Service.
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March Humidity in O'Fallon

In O'Fallon in March, humidity is 80%. With an average temperature of 8°C (47°F), this humidity feels like you're walking through a heavy mist, making your clothes cling to your skin and every step prone to a shiver, which can be quite uncomfortable for traveling.

March Average Humidity in O'Fallon

This chart illustrates the average monthly humidity levels in O'Fallon, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in O'Fallon is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%80%80%80%82%83%81%80%76%76%85%86%
Data source: Humidity data for March generated using information from the Copernicus Climate Change Service.

March UV Index in O'Fallon

In O'Fallon in March, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in O'Fallon, you can refer to this Hourly UV Index in O'Fallon.

Maximum UV Index Levels in O'Fallon for March

The chart shows the monthly maximum UV Index (UVI) for O'Fallon in March, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In March, the maximum UV index in O'Fallon typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3569101111109653
Data source: O'Fallon March UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How March Weather in O'Fallon Compares to Other Months

Weather in O'Fallon varies notably across the year, with each month offering distinct climate conditions. This page compares March’s weather to other months in O'Fallon, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in O'Fallon, showing how March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather0°C (32°F)72 mm (2.9 inches)82%moderate
February Weather2°C (35°F)78 mm (3.1 inches)80%moderate
March Weather8°C (47°F)128 mm (5.0 inches)80%high
April Weather13°C (55°F)121 mm (4.8 inches)80%very high
May Weather19°C (67°F)145 mm (5.7 inches)82%very high
June Weather25°C (76°F)84 mm (3.3 inches)83%extreme
July Weather26°C (80°F)97 mm (3.8 inches)81%extreme
August Weather24°C (76°F)139 mm (5.5 inches)80%very high
September Weather22°C (72°F)56 mm (2.2 inches)76%very high
October Weather15°C (59°F)110 mm (4.3 inches)76%high
November Weather7°C (44°F)68 mm (2.7 inches)85%moderate
December Weather4°C (39°F)52 mm (2.1 inches)86%moderate

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