Sullivan (MO) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Sullivan.
Climate overview of Sullivan
The climate in Sullivan, Missouri, United States of America, is marked by large temperature swings across the seasons, ranging from 31°C (88°F) in July to 6°C (43°F) in January.
The city has a wet climate, receiving around 1125 mm (44 in) of rain/snowfall per year. Despite the high annual total, it has very warm summers and cold winters. May is the wettest month.
Sullivan Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Sullivan - and find the best time to visit.
Monthly Temperature in Sullivan
In Sullivan, temperatures differ significantly between summer and winter months. On average, daytime temperatures range from a very warm 31°C (88°F) in July to a chilly 6°C (43°F) in January.
Nighttime temperatures range from 19°C (66°F) in July to -6°C (21°F) in January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Sullivan
Sullivan experiences significant rain/snowfall throughout the year, averaging 1125 mm (44 in) of precipitation annually. The seasons in Sullivan bring significant changes in precipitation. The wettest month, May, receives high rainfall, with an average of 131 mm (5.2 in) of precipitation. This rainfall is distributed across 14 rainy days.
In contrast, the driest month, January, experiences much less snow/rainfall, totaling 49 mm (1.9 in) over 6 snowy/rainy days. These distinct seasonal differences provide diverse experiences throughout the year. For more details, please visit our Sullivan Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Best Time to Visit Sullivan
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: October
- Warmest weather: July and August
- Fewest rainy days: January, October and November
- Seasonal pattern: Very warm summers and cold winters
- Coldest conditions: January, with freezing nights around -6°C (21°F).
Frequently asked questions about the climate in Sullivan
What is the best time to visit Sullivan?
October typically offers the most optimal weather in Sullivan. In contrast, January, February and December tend to have less optimal conditions. Sullivan has very warm summers and cold winters.
What temperatures can I expect in Sullivan?
Daytime highs range from 6°C (43°F) in January to 31°C (88°F) in July. Nighttime lows range from -6°C (21°F) to 19°C (66°F). Temperatures vary considerably through the year.
How much rain does Sullivan get?
Annual rainfall is around 1125 mm (44 in). May is the wettest month with 131 mm (5.2 in), while January is the driest with 49 mm (1.9 in).
Sullivan 3-Day Forecast
Sullivan (MO) 3-Day Forecast
Sullivan on the map
Sullivan is highlighted - select any city to see its climate.
Popular this month
Where to go in July - average daytime high across popular destinations.
Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
Yosemite National Park is definitely worth a visit
Vast forests, blue lakes, towering sequoias, and majestic waterfalls hint at the beauty of Yosemite National Park—a true natural masterpiece.
The 10 most alternative cities in the United States
Discover the top 10 fun and alternative U.S. cities rich in art, culture, and adventure. From Portland's hippy charm to Sedona's stunning landscapes.
Sedona: Explore Majestic Red Rock Landscapes
A picturesque artists' town surrounded by red rocks and known for its spirituality, vortex energy, and stunning hikes like Cathedral Rock.
10 most idyllic villages to visit in the United States
Discover 10 idyllic villages in the USA, from California to Vermont. Explore their unique charm, rich history, stunning nature, and vibrant arts scenes.