Climate Insights for Bay Saint Louis

The climate in Bay Saint Louis is warm and mild. The average annual temperature is 21°C and approximately 1597mm of precipitation falls per year. Bay Saint Louis receives a notable amount of rainfall throughout the year, including during its driest month. Bay Saint Louis is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, June. The coldest months are January, February, December, when temperatures can drop to 9°C.

Temperatures in Bay Saint Louis vary considerably across the year, with a 21°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 30°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 9°C and an average of 12°C. Daily temperature variation is modest, with an average difference of 4°C between highs and lows. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.

Bay Saint Louis is a fairly wet location, receiving approximately 1597mm of precipitation annually, which averages out to around 133mm per month. The wettest month is August, averaging 208mm of rainfall. June and July also tend to see above-average precipitation. The driest month is October, with just 91mm. That's 116mm less than August, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around.

Bay Saint Louis is moderately windy, with an average annual wind speed of 21km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 24km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in July, with average winds dropping to 17km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 7km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 23km/h in winter, 23km/h in spring, 18km/h in summer, 20km/h in autumn.

It is currently spring in Bay Saint Louis, which began on March 20, 2026. Bay Saint Louis is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 30°C, while the coldest stretch bottoms out in January near 9°C. Summer is next, beginning on June 21, 2026 — 87 days from now.

The best time to visit Bay Saint Louis is during October and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 95mm per month. By contrast, August can be uncomfortably hot with highs reaching 30°C, while January is the coldest period with lows dropping to 9°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Bay Saint Louis based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.