The best times to visit Mount Vernon for ideal weather are

April 16th to June 17th


August 13th to October 21st

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



Other Mount Vernon Travel Info

Weather in Mount Vernon


Average temperatures in Mount Vernon vary drastically. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a low chance of precipitation most of the year. The area is somewhat temperate — in the 41st 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 Mount Vernon, 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 89.9°F (32.2°C) with temperatures rarely dropping below 66.9°F (19.4°C) at night.

Mount Vernon Temperatures (Fahrenheit)


Mount Vernon 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.

Mount Vernon Perceived Temperature (F)


Mount Vernon Perceived Temperature (C)



Average Mount Vernon 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 40.3 30.4 22
Feb 42.4 32.3 23.9
Mar 58.1 45.9 36
Apr 68.9 56.3 45.2
May 77.3 65.5 54.7
Jun 86.6 74.5 63.2
Jul 88.8 76.3 65.2
Aug 88.3 75.2 63.7
Sep 81.5 67.6 56.5
Oct 69.7 55.8 44.2
Nov 56 44.3 33.9
Dec 45.1 36.2 28.3

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 4.6 -0.9 -5.6
Feb 5.8 0.2 -4.5
Mar 14.5 7.7 2.2
Apr 20.5 13.5 7.3
May 25.2 18.6 12.6
Jun 30.3 23.6 17.3
Jul 31.6 24.6 18.4
Aug 31.3 24 17.6
Sep 27.5 19.8 13.6
Oct 20.9 13.2 6.8
Nov 13.3 6.8 1.1
Dec 7.3 2.3 -2.1



Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Mount Vernon are January, October, and then September. 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 are no days of precipitation on average. By contrast, it’s most likely to rain or snow in early to mid June with an average of 2 days of significant precipitation the week of June 11th.

When can you find snow in Mount Vernon? Weather stations report no annual snow. 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 Mount Vernon.

Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Mount Vernon (in).

Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 6% 0 1.1
Feb 8% 0 0.9
Mar 14% 0 2.1
Apr 16% 0 3
May 17% 0 2.9
Jun 19% 0 3.9
Jul 11% 0 2.4
Aug 9% 0 2.1
Sep 7% 0 1.5
Oct 7% 0 1.5
Nov 10% 0 2.3
Dec 14% 0 3.3

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 6 0 2.8
Feb 8 0 2.3
Mar 14 0 5.3
Apr 16 0 7.6
May 17 0 7.4
Jun 19 0 9.9
Jul 11 0 6.1
Aug 9 0 5.3
Sep 7 0 3.8
Oct 7 0 3.8
Nov 10 0 5.8
Dec 14 0 8.4


Humidity and Wind

Mount Vernon has some high humidity months, with other comfortably humid months. The least humid month is April (51.7% relative humidity), and the most humid month is December (65.8%).

Wind in Mount Vernon is usually calm. The windiest month is April, followed by March and January. April’s average wind speed of around 6.1 knots (7 MPH or 11.3 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early to mid April where average top sustained speeds reach 15.4 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Mount Vernon.

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 5.6 Light breeze 12.4 Significant breeze
Feb 5.5 Light breeze 12.9 Significant breeze
Mar 6 Light breeze 13.6 Significant breeze
Apr 6.1 Light breeze 14.7 Significant breeze
May 4.8 Light breeze 12.4 Significant breeze
Jun 4.4 Light breeze 12 Significant breeze
Jul 3.7 Barely noticeable 10.4 Significant breeze
Aug 3.4 Barely noticeable 10 Gentle breeze
Sep 3.5 Barely noticeable 10.1 Significant breeze
Oct 4.3 Light breeze 11.5 Significant breeze
Nov 5 Light breeze 12.1 Significant breeze
Dec 5.2 Light breeze 11.9 Significant breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 59.3%
Feb 57.7%
Mar 54.4%
Apr 51.7%
May 60.1%
Jun 60.6%
Jul 63.6%
Aug 62.8%
Sep 62.8%
Oct 57.4%
Nov 58.3%
Dec 65.8%


Is it Safe to Travel to Mount Vernon?

Our best data indicates this area is generally safe. As of Oct 07, 2019 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 Sep 23, 2019.


The Busiest and Least Crowded Months

The busiest month for tourism in Mount Vernon, IL, US is July, followed by June and May. 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 Mount Vernon in January. 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 50.2 in January means 50.2% of the tourists vs. July.



Overall Mount Vernon Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderate. Highs range from 82.6°F (28.1°C) and 46.7°F (8.2°C) with warmer temperatures in the later months. Rain is somewhat common with 4 to 5 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 3 to 6 days of precipitation per month. June – August is the busiest season for tourism in Mount Vernon, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 84.2°F (29°C) and 49.7°F (9.8°C), which will feel chilly given the humidity and wind. It rains or snows a normal amount: 2 to 3 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 Mount Vernon to be enjoyable for warm weather travelers. The average high during this season is between 46.7°F (8.2°C) and 39.3°F (4.1°C). On average, it rains or snows a smalll amount: 2 to 4 times per month. These times of year are fairly slow with tourists.


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