The best times to visit St Charles for ideal weather are

April 16th to June 3rd

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.



Other St Charles Travel Info

Weather in St Charles


Average temperatures in St Charles vary drastically. Considering humidity, temperatures feel nice between summer and winter. The temperatures feel cold for about half the year, and too hot for part of the year with a chance of rain or snow throughout most of the year. The area is less temperate than some — in the 21st percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit St Charles, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally mid July where highs are regularly around 92.4°F (33.6°C) with temperatures rarely dropping below 71.3°F (21.8°C) at night.

St Charles Temperatures (Fahrenheit)


St Charles Temperatures (Celsius)


“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

St Charles Perceived Temperature (F)


St Charles Perceived Temperature (C)



Average St Charles Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 43.5 31.6 21.8
Feb 45.4 33.1 23
Mar 61.4 47.9 36.6
Apr 71.6 58.4 45.9
May 80 68.5 57.4
Jun 88.7 77.7 67.1
Jul 91.3 80.5 69.9
Aug 90.8 79.5 68.9
Sep 83.4 71.2 60.4
Oct 72 59.3 47.9
Nov 59.7 47.4 36.8
Dec 47.1 37.1 28.1

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 6.4 -0.2 -5.7
Feb 7.4 0.6 -5
Mar 16.3 8.8 2.6
Apr 22 14.7 7.7
May 26.7 20.3 14.1
Jun 31.5 25.4 19.5
Jul 32.9 26.9 21.1
Aug 32.7 26.4 20.5
Sep 28.6 21.8 15.8
Oct 22.2 15.2 8.8
Nov 15.4 8.6 2.7
Dec 8.4 2.8 -2.2



Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in St Charles are January, August, and then November. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around mid January. For example, on the week of January 15th there is 1 day of precipitation on average. By contrast, it’s most likely to rain or snow in late May with an average of 2 days of significant precipitation the week of May 21st.

When can you find snow in St Charles? Weather stations report a good amount of seasonal snow likely to be deepest around January, especially close to mid March. The best time to ski (if at all) in St Charles is often around around March 19th when fresh powder is deepest. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in St Charles.

Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in St Charles (in).

Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 12% 2.9 1.9
Feb 19% 2.1 2.7
Mar 24% 2.6 3.8
Apr 28% 0 5.6
May 31% 0 4.9
Jun 28% 0 6.2
Jul 21% 0 4.1
Aug 17% 0 3.2
Sep 18% 0 4.3
Oct 19% 0 3.2
Nov 17% 1.4 3.2
Dec 21% 1.9 3.9

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 12 7.4 4.8
Feb 19 5.3 6.9
Mar 24 6.6 9.7
Apr 28 0 14.2
May 31 0 12.4
Jun 28 0 15.7
Jul 21 0 10.4
Aug 17 0 8.1
Sep 18 0 10.9
Oct 19 0 8.1
Nov 17 3.6 8.1
Dec 21 4.8 9.9


Humidity and Wind

St Charles has some comfortably humid months, with slightly drier months on the other side of the year. The least humid month is April (46.9% relative humidity), and the most humid month is December (59.9%).

Wind in St Charles is usually moderate. The windiest month is April, followed by February and March. April’s average wind speed of around 8.8 knots (10.2 MPH or 16.3 KPH) is considered “a gentle breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in late April where average top sustained speeds reach 17.3 knots, which is considered a fresh breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in St Charles.

Avg. Relative Humidity


The graph below shows wind speed (max and average) in knots.

Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 8.4 Gentle breeze 15.1 Significant breeze
Feb 8.4 Gentle breeze 15.5 Significant breeze
Mar 8.4 Gentle breeze 15.4 Significant breeze
Apr 8.8 Gentle breeze 16.7 Significant breeze
May 7.4 Gentle breeze 15.2 Significant breeze
Jun 6.9 Light breeze 15.3 Significant breeze
Jul 6.1 Light breeze 12.8 Significant breeze
Aug 5.7 Light breeze 12.1 Significant breeze
Sep 5.6 Light breeze 11.9 Significant breeze
Oct 7 Gentle breeze 13.5 Significant breeze
Nov 7.6 Gentle breeze 14.2 Significant breeze
Dec 7.9 Gentle breeze 14.4 Significant breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 52.3%
Feb 52%
Mar 49.7%
Apr 46.9%
May 52.7%
Jun 54.4%
Jul 53.5%
Aug 53.5%
Sep 54.9%
Oct 51.5%
Nov 50.7%
Dec 59.9%


Is it Safe to Travel to St Charles?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Dec 04, 2023.


The Busiest and Least Crowded Months

The busiest month for tourism in St Charles, MO, US is July, followed by June and August. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit St Charles in November. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month


Most Popular Months to Visit

Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 38.7 in November means 38.7% of the tourists vs. July.



Overall St Charles Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderate. Highs range from 85.5°F (29.7°C) and 48.9°F (9.4°C) with warmer temperatures in the later months. Rain is somewhat common with 8 to 10 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see moderate precipitation with 5 to 8 days of precipitation per month. June – August is the busiest season for tourism in St Charles, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 86.3°F (30.2°C) and 53.6°F (12°C), which will feel comfortable given the humidity and wind. It rains or snows a significant amount: 5 to 6 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.

Winter (December through February)

Weather is far too cold this time of year in St Charles to be enjoyable for warm weather travelers. The average high during this season is between 48.9°F (9.4°C) and 43.1°F (6.2°C). On average, it rains or snows a fair amount: 4 to 7 times per month. These times of year are fairly slow with tourists.


Best Times to Travelthe United States › St Charles, MO, US