St. Louis, Missouri, experiences a diverse climate with distinct seasons, making it a unique place to visit year-round. Summers are typically hot, with July being the warmest month, where average highs reach 89°F and lows hover around 70°F.
Winters can be quite cold, especially in January, the coldest month, when temperatures range from a high of 41°F to a low of 25°F.
Spring and fall provide the most mild and comfortable weather in St. Louis.
During these seasons, temperatures are moderate and the humidity is lower.
April and May offer pleasant conditions, with temperatures generally ranging from 47°F to 67°F. Similarly, fall months like September and October have temperatures that make strolling through the city an enjoyable experience.
Rainfall varies throughout the year, with an annual average of about 41 inches.
August tends to be a hot month, often reaching an average temperature of 79°F, peaking at 88°F on the hottest days.
Whether you’re planning a summer trip or a cozy winter visit, understanding St. Louis’s climate will help you make the most of your stay.
Average Temperature In St. Louis, Missouri
In St. Louis, temperatures vary greatly throughout the year.
The temperatures in the summer are often warm, with July being the hottest month. The average high in July is 89°F. During this month, temperatures can occasionally reach up to 97°F.
In contrast, winter brings very cold weather. January is the coldest month with an average low of 25°F. Occasionally, temperatures can drop as low as 9°F, which makes it a chilly time of the year.
| Month | Average High (°F) | Average Low (°F) |
|---|---|---|
| January | 41 | 25 |
| February | 45 | 29 |
| March | 56 | 39 |
| April | 67 | 49 |
| May | 76 | 59 |
| June | 85 | 68 |
| July | 89 | 72 |
| August | 88 | 70 |
| September | 81 | 62 |
| October | 70 | 50 |
| November | 56 | 39 |
| December | 44 | 28 |
Monthly temperatures show a significant difference between summer and winter. For more detailed data on average temperatures, check out the temperature information.
St. Louis experiences both high and low temperatures throughout the year, making it important to prepare for a range of weather conditions. The variability ensures that residents experience a mix of seasons.
Average Precipitation In St. Louis, Missouri
St. Louis experiences significant rainfall throughout the year, along with some snowfall in the colder months. The city has a warm and temperate climate with precipitation spread fairly evenly across the seasons.
Average Rainfall In St. Louis, Missouri
Rainfall in St. Louis varies between months but remains relatively consistent overall. The average annual rainfall is about 41 inches.
The wettest month is May, with around 4.6 inches of rain.
Summer months, such as June and July, also see substantial rainfall, reaching nearly 4 inches each month.
Rainfall patterns are influenced by warm, moist air from the Gulf of Mexico.
Spring and summer have frequent thunderstorms, contributing to seasonal rain totals.
Winter months see less rain but still average about 2.5 inches each month.
Rain is crucial for maintaining the lush greenery and supporting agriculture in the region.
Average Snow In St. Louis, Missouri
Snowfall in St. Louis occurs mainly between December and February. The city’s average annual snowfall is about 18 inches. January sees the most snow, with an average of around 5 inches for the month.
Snow events can vary, from light dustings to heavy snowstorms that occasionally disrupt daily activities.
Typically, snowfall is quickly cleared from roads and public spaces to minimize disruptions.
Schools and businesses may close during significant snowfall. Understanding the patterns of snow and ice is essential for residents to prepare adequately.
Average Sun In St. Louis, Missouri
St. Louis experiences a mix of sunny and cloudy days throughout the year. The region has varying sunshine hours and daily solar energy depending on the season.
Average Daily Shortwave Solar Energy In St. Louis, Missouri
St. Louis receives different amounts of shortwave solar energy at various times of the year.
In June, the city peaks with approximately 6.6 kWh per square meter. December sees the lowest levels, averaging around 2.3 kWh per square meter. These variations affect how much direct sunlight reaches the ground.
Sunshine hours also vary, with clear days more frequent in summer.
On average, St. Louis gets about 101 sunny days per year.
Sunny days are less common in winter, with cloud cover being more persistent.
The sunshine hours in St. Louis contribute to the temperatures and overall climate patterns.
This means longer days in summer, increasing temperatures and creating hotter conditions.
In contrast, shorter days in winter limit the amount of daily sunlight, contributing to colder weather.
Average Humidity In St. Louis, Missouri
St. Louis experiences varying humidity levels throughout the year. The average annual relative humidity in St. Louis is 68%.
Humid Months:
- December: The most humid month with an average humidity of 74%. This makes the air quite moist and can feel colder than the actual temperature during winter.
Less Humid Months:
- April: The least humid month, with an average humidity of 63%. This makes spring a more comfortable time for those sensitive to humidity.
| Month | Average Humidity (%) |
|---|---|
| January | 71 |
| February | 67 |
| March | 65 |
| April | 63 |
| May | 66 |
| June | 67 |
| July | 67 |
| August | 68 |
| September | 68 |
| October | 68 |
| November | 70 |
| December | 74 |
Daily Variations:
Humidity levels can also vary from morning to evening. Typically, mornings are more humid, while evenings tend to be less humid. This pattern results in different comfort levels throughout the day.
St. Louis’ climate, including humidity, makes it important to plan activities accordingly. For further details, refer to the average humidity information for St. Louis.
Average Wind In St. Louis, Missouri
St. Louis experiences moderate winds throughout the year. The average wind speed is around 8 mph.
The wind is usually calm in the summer. It tends to be brisker during the fall and winter months. This makes autumn and winter the windiest months of the year.
Spring tends to have variable wind speeds. While generally mild, strong gusts can occur.
Wind directions vary but predominantly come from the south during the summer. Winter months often see winds coming from the northwest.
Wind conditions can impact outdoor activities like sailing and cycling.
It can be wise to check local forecasts before planning such activities. Wind statistics can provide useful insights.
| Month | Average Wind Speed (mph) |
|---|---|
| January | 10 |
| February | 10.5 |
| March | 11 |
| April | 10.5 |
| May | 9 |
| June | 8 |
| July | 7.5 |
| August | 7 |
| September | 8.5 |
| October | 9.5 |
| November | 10 |
| December | 10.5 |
Wind speed impacts temperature perception. On windy days, it can feel cooler than it is. The wind chill factor becomes more significant in winter.
Average Air Quality In St. Louis, Missouri
The air quality in St. Louis, Missouri, is an important aspect of the local climate. The city’s air quality is monitored regularly to ensure it remains safe for residents and visitors.
Air Quality Index (AQI) Levels
St. Louis often experiences Good air quality. This means the air is generally safe to breathe. The Saint Louis Air Quality Index is updated in real-time to reflect current conditions.
Common Pollutants
The primary pollutants tracked include:
- PM2.5 (Fine particulate matter)
- Ozone
- Nitrogen Dioxide (NO2)
- Sulfur Dioxide (SO2)
These pollutants are measured to ensure they stay within healthy levels.
Effect of Weather
Weather plays a significant role in the air quality of St. Louis.
Factors like temperature, wind speed, and atmospheric pressure can influence the concentration of pollutants.
For example, higher temperatures can increase ozone levels.
Seasonal Variations
In summer, the air quality can be affected by higher temperatures and increased sunlight, leading to higher ozone levels.
In winter, pressure systems can cause pollutants to linger closer to the ground, sometimes worsening air quality.
Monitoring and Reporting
St. Louis has several monitoring stations that provide real-time data.
Residents can access localized information to make informed decisions about outdoor activities.
For instance, the St. Louis Air Quality Map offers comprehensive summaries and real-time analysis.
Topography Of St. Louis, Missouri
St. Louis is located in the eastern part of Missouri.
The city sits near the Missouri-Mississippi confluence.
The landscape features bluffs and terraces rising 100-200 feet above the Mississippi River.
These natural formations provide unique scenery and elevation changes.
Elevation
Most of the area has rolling prairies and fertile land.
This makes it suitable for agriculture and urban development.
Terrain
St. Louis includes both urban and leafy suburban areas.
The city has gently rolling terrains.
The topography affects the local climate, contributing to temperature variations.
Notable High Points
- Valley Park Pettys Hill: Elevation of 482 feet
Despite its urban environment, St. Louis is surrounded by natural features that offer various outdoor activities.
The terrain and elevation make the city unique in the Midwest.
Extreme Weather Events That Occur In St. Louis, Missouri
St. Louis, Missouri, experiences a variety of extreme weather events.
The region’s winters can be quite harsh, often bringing freezing temperatures that stay below 32°F for extended periods.
For instance, the coldest start recorded was in recent years, with temperatures remaining below freezing for twelve consecutive days.
Thunderstorms are common in the spring and summer months.
These storms often bring heavy rain, strong winds, and sometimes hail.
Hailstones can range from the size of peas to golf balls, causing significant damage to property.
Tornadoes are another concern in St. Louis.
The city’s location in the Midwest makes it susceptible to these dangerous atmospheric phenomena.
Tornadoes can occur suddenly, bringing winds of over 100 miles per hour and causing extensive damage.
Summers can be extremely hot, sometimes reaching over 100°F.
During these hot months, electrical storms are frequent.
These storms can cause power outages and pose a risk to individuals outdoors.
Cold weather isn’t limited to just winter months.
Early spring and late fall can also see sudden drops in temperature.
For example, it’s not uncommon to experience cold fronts that bring the temperature down to the 30s in late October.
In recent years, there has been an increase in extreme weather events due to climate change.
This includes more frequent and intense storms, such as the heavy rains that led to severe flooding in July 2022.
These floods caused significant damage and highlighted the city’s vulnerability to changing weather patterns.
Heavy rainfall can lead to flash flooding, particularly in low-lying areas.
Such events can overwhelm the local infrastructure, leading to road closures and property damage.
The impact of these floods can be long-lasting for the residents of St. Louis.
Best Time Of The Year To Visit St. Louis, Missouri
The best time to visit St. Louis, Missouri is during the spring and fall months. The weather is pleasant, making it ideal for outdoor activities and exploring the city.
What Is St. Louis, Missouri Like In Spring
Spring in St. Louis spans from April to May. The temperatures are mild and range from the mid-50s to mid-70s Fahrenheit.
This season is known for its blooming flowers and green landscapes, making it perfect for visiting parks and gardens like the Missouri Botanical Garden.
Rainfall can be frequent, so it’s a good idea to carry an umbrella.
The city hosts several outdoor events and festivals during these months, adding to the vibrant atmosphere.
The lower humidity levels also make it comfortable for walking tours and sightseeing.
What Is St. Louis, Missouri Like In Summer
Summer runs from June to August and is marked by hot and humid conditions.
Temperatures often range from the upper 70s to the low 90s Fahrenheit. July is typically the hottest month with temperatures sometimes exceeding 95°F.
Despite the heat, summer is a popular time for tourism.
Outdoor concerts, ball games, and water activities at places like Forest Park or the Gateway Arch are common.
Be prepared for occasional thunderstorms, and make sure to stay hydrated and wear sunscreen.
What Is St. Louis, Missouri Like In Fall
Fall, from September through October, is another great period to visit St. Louis.
The weather is similar to spring, with temperatures ranging from the 60s to the low 80s Fahrenheit. The fall foliage transforms the city’s parks and neighborhoods into a colorful landscape.
Both locals and tourists enjoy activities like apple picking and attending harvest festivals.
The cooler weather makes it a good time for outdoor cafes and patio dining. Visitors can also enjoy the Wine Country tours located a short drive from the city.
What Is St. Louis, Missouri Like In Winter
Winter, from December to March, is the least popular time to visit due to cold temperatures and wind. Lows can drop to around 24°F, and highs typically don’t exceed 56°F.
Snowfall is occasional but can disrupt travel plans.
Despite the cold, winter offers quieter attractions with fewer crowds.
Indoor activities such as museum visits, theater shows, and exploring local cuisine are popular choices.
Discounted hotel rates can also be a perk for travelers willing to brave the chill.
For more detailed information and travel tips, you can refer to Best Times to Visit St. Louis | U.S. News Travel, The Best & Worst Times to Visit St. Louis, and Best Time to Visit St. Louis.