O'Fallon weather in May (Illinois, United States of America)

Thinking of visiting O'Fallon in May? Check the weather first! Our guide gives you the essential weather details for this month.

Temperatures

The typical weather for May in O'Fallon includes high temperatures and high rainfall. Throughout the day, temperatures can rise to about 25°C. At night, they generally drop to 14°C.

Precipitation

O'Fallon in May usually receives high rainfall, averaging around 129 mm for the month. Records from the past 30 years suggest that around 14 days will experience rain.

Average sunshine

The days are predominantly sunny, with an estimated total of around 269 hours of sunshine. These sun-filled days are perfect for spending time outside. Whether it's playing sports, visiting a park, or going for a bike ride.

In case you lean more towards enjoying temperate temperatures and rain-free days October typically offers the most optimal weather. In contrast, January, February and December tend to have less optimal conditions.

For an in-depth look at the yearly conditions, visit our specialized O'Fallon climate page with graphs.

 

O'Fallon, monthly averages in May

Min Temperature 14°C  

Max Temperature 25°C  

Chance of Rain 47%  

Precipitation 129 mm  

Rainy days 14 days  

Humidity 65% *  

Sunshine 269 hours *  

Percentage Sunshine 60% *  

Data from: St. Louis, the United States of America (25 KM, 15 Miles).

Where to go in the United States of America in May

Find out more about the weather in the United States of America and which places have the best travel conditions in this month.

Weather conditions Weather

Temperatures

Precipitation

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Legend perfect weather pleasant tolerable unpleasant poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

So, what should you wear in this month?

For visitors traveling to O'Fallon, we recommend wearing layers. So maybe a skirt, t-shirt, shorts for during the day and jeans and a warm jacket for some days and evenings. Bring a rain jacket in case it rains during your stay. Plan on layering your clothes.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

9/10

Walking

9/10

Camping

6/10

Outdoor sports

9/10

Interested in more climate information?

This site provides you with all the information you need about the climate in O'Fallon.

Our site offers climate and forecast data for every country in the world. Are you going to the United States of America? On this website you can find historical weather averages for many cities in the United States of America. Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.