St. Charles, MO weather and climate in 2024
Day
25 °C
Night
12 °C
Sea
0 °C
Precipitation
116 mm
in month
Rainy days
12 days
in month
Daylight
14 hours
average
Sunshine
9 hours
average
Humidity
68 %
Day
25 °C
Night
12 °C
Sea
0 °C
Precipitation
116 mm
in month
Rainy days
12 days
in month
Daylight
14 hours
average
Sunshine
9 hours
average
Humidity
68 %
Overview: St. Charles, MO
Weather charts for St. Charles, MO
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Weather overview for St. Charles, MO
Weather overview
Across the diverse seasons in St. Charles, MO, temperatures range from frosty winters with lows averaging -6.1°C to warm and toasty summers where highs can reach 31.5°C. Rain is a constant companion year-round, with rainfall peaking in May and the least in January. Winds sweep through the region with more gusto in the cooler months, while calm, balmy breezes mark the summer. The humidity varies modestly throughout the year, with a slight rise during the summer months due to increased precipitation. Days are shortest in December and lengthen to a generous stretch by June, offering plenty of sunlight for outdoor activities.
January weather
January in St. Charles ushers in the new year with brisk temperatures, averaging a modest high of 4.3°C. Moderate precipitation marks the month, and the winds can be quite nippy at 4 m/s – enough to make you want to bundle up tightly. The number of wet days is kept to a minimum, though, with rain typically falling on just over 7 days throughout the month.
February weather
February might still be snuggled in winter's chill with an average high of 7°C, but St. Charles starts to see a subtle shift towards spring. With a slight decrease in wind speeds to 3.8 m/s, it feels a tad less biting. Rain falls consistently, though slightly less than the preceding month, occurring over approximately 7.6 days.
March weather
With the arrival of March, St. Charles experiences a more pronounced warming trend, reaching an average high of 13.1°C. The breezes soften just a bit more from the harsh winter gusts, blowing at around 4 m/s. Rainy days inch up, hitting double digits with an average of 10.4 wet days, so keep your umbrella handy.
April weather
April showers bring May flowers to St. Charles, with the average high reaching a pleasant 19.6°C. Rain is frequent and plentiful, falling over approximately 10.7 days totaling nearly 98 mm. Gentle winds at roughly 4.3 m/s complement the increasingly warm and damp days of early spring.
May weather
May marks the entrance of warmer weather in St. Charles, with daytime highs peaking at 24.5°C. This month records the highest average precipitation at over 116 mm, distributed across approximately 12.4 wet days. Lighter breezes prevail, setting the stage for a muggy feeling as the relative humidity averages 67.5%.
June weather
The onset of summer in June sees temperatures soaring to a comfortable high of 29.2°C in St. Charles. Rainfall is still prominent, though slightly reduced from May, with around 96.3 mm falling over 11.1 days. Gentle summer winds at 2.8 m/s and the highest average sun hours at 9.7 hrs per day make for a delightful season.
July weather
July heats up in St. Charles, MO, boasting the highest temperatures of the year, with an average high of 31.5°C. It also has one of the lowest wind speeds at 2.5 m/s, creating sultry conditions. Rainfall remains significant, though slightly less frequent with an average of 104.2 mm over 9.4 wet days.
August weather
August in St. Charles slightly dials back the heat, with an average high of 30.9°C. The calm winds continue at 2.5 m/s, and the humidity may contribute to a rather sticky atmosphere. Rain tends to fall over approximately 9.3 days with a total of 80.9 mm for the month.
September weather
September welcomes the beginning of autumn with a notable change in the weather. The average high tempers to a comfortable 26.9°C in St. Charles. Although the winds remain steady at 2.5 m/s, the rainfall begins to recede, averaging 83 mm spread across around 8 wet days.
October weather
October's crispness is felt in St. Charles as temperatures continue to decline to an average high of 20.5°C. The wind picks up a bit to 3.2 m/s, reinforcing the autumnal transition. Precipitation is relatively consistent, but not heavy, occurring over 8.2 days, with 81.2 mm of rain.
November weather
November sees the steady march towards winter with daytime highs dipping to an average of 13.2°C in St. Charles. Winds intensify slightly at 3.8 m/s, and the rainfall is similar to October, totaling around 89.5 mm over 9.1 days. Layers become essential as the temperature shows wider fluctuations between day and night.
December weather
December marks the return of winter's grip on St. Charles, with chilled days averaging a high of 5.8°C. Rains are slightly less frequent than in November, with 8 wet days and an average precipitation of 72.4 mm. Wind speeds persist at 3.8 m/s, creating a sharp edge to the wintery air.
FAQs
Will I need a warm coat in St. Charles during January?
Absolutely, a warm coat is essential in St. Charles during January, with night temperatures plunging to around -6.1°C. Layering is also recommended due to the maximum daytime temperature being just over freezing at 4.3°C.
Is February much warmer than January in St. Charles?
February is marginally warmer, with a daytime high average of 7°C versus January's 4.3°C. Nights remain cold, but you'll feel the gradual transition towards warmer days.
What's the difference in temperature between day and night in St. Charles during March?
March offers a considerable temperature swing, with daytime highs averaging 13.1°C and night lows averaging 1°C. This spread indicates that while days are milder, nights can retain a bit of winter's chill.
How warm is it during the day in St. Charles in April?
April days in St. Charles are quite warm with an average high of 19.6°C. The ascent of spring temperatures makes it an agreeable time for outdoor activities.
What are typical day temperatures in St. Charles during May?
Daytime temperatures in May in St. Charles are quite pleasant, with an average high of 24.5°C. It's warm enough to enjoy the outdoors, but not so hot as to be uncomfortable.
How hot does it get in St. Charles in June?
June in St. Charles is quite warm, with daytime temperatures climbing to an average high of 29.2°C. The approach of peak summer is definitely felt during this month.
What kind of temperatures can I expect in St. Charles during the month of July?
Expect hot summer days in July with the temperatures peaking at an average high of 31.5°C. The nights offer a slight reprieve with a warmer average low of 19.4°C.
Does August see a dip in temperatures in St. Charles compared to July?
Yes, August experiences a modest decrease in temperatures with daytime highs averaging 30.9°C, ever so slightly cooler than July's peak.
How does the weather begin to change in St. Charles during September?
September ushers in noticeable weather changes with cooler average high temperatures of 26.9°C, signifying the gradual approach of fall. The air may carry a fresh crispness not felt during the height of summer.
What should I expect from October temperatures in St. Charles?
October offers a range of temperatures, with pleasant daytime highs around 20.5°C. You'll feel the need for a light jacket, especially as evening temperatures begin to cool off noticeably.
As winter approaches, how cold does it get in St. Charles in November?
November brings cooler days with an average high of 13.2°C and chilling night lows averaging 1.7°C. It's the time to start transitioning into heavier clothing.
Just how cold does December get in St. Charles?
December is indeed cold in St. Charles, with average highs around a chilly 5.8°C. The nighttime temperatures average -4.2°C, a clear signal to don winter-warm attire.
We make the most from 40 years of historical weather data to predict the best weather conditions.
Deciding on where to go for a holiday is hard sometimes. Get inspired by the most popular destinations.
We aggregate data from combining multiple weather sources to ensure accuracy of the highest order.