Hurricanes and Tornadoes That Hit Bay St Louis, MS

The nearest NOAA station with 1991–2020 climate normals is Waveland, MS, 2 miles southeast of Bay St Louis at 8 feet. August is the warmest, with an average high of 89°F and low of 74°F; January is the coolest, at 59°F and 42°F. July is the wettest at 7.7 inches of precipitation on average and October the driest at 3.5 inches; the year adds up to 65.0 inches over 76 days with at least a tenth of an inch. June to November, the hurricane season months, bring 51% of the year's precipitation (33.4 of 65.0 inches); the other six months are drier. September has brought the most of the 73 tropical systems that passed within 75 miles (33); a normal September there has highs of 86°F and 5.7 inches of precipitation. Highs reach 90°F on about 47 days a year, almost all from May to September. Lows fall below freezing on about 17 nights a year. That 65.0 inches is more than at 79 of the 87 Mississippi stations used on this site (91%). Long Beach, 15 miles east, has its own station (Gulfport Naval Ctr, MS): 68.3 inches a year, 3.3 more than here, and an August average high of 90°F against 89°F.

Water temperature at the NOAA tide station Bay Waveland Yacht Club, MS, 5 miles east, averaged 87°F in July and August and 54°F in January over 2021–2025. It averaged 80°F or warmer from June to September. Sea level at the Bay Waveland tide gauge, 5 miles from Bay St Louis, has risen 1.81 ± 0.13 inches per decade from 1978 to 2025, NOAA's linear trend; at that pace it is 18.1 inches in a hundred years. That is faster than at 112 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 92 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Bay St Louis: 65 thunderstorm wind reports, 22 flash floods, 2 heavy rain events, 2 lightning strikes and 1 flood. None is recorded as killing or injuring anyone; the NWS estimated $400,000 in property and crop damage. The strongest thunderstorm gust on record here was 70 mph, on March 9, 2011. June has had the most flash floods, 8 of 22. Of the 232 Mississippi cities on this site with a flash flood on record, 145 have had fewer than Bay St Louis.

Flood insurance policyholders in Bay St Louis's ZIP code 39520 have filed 6,050 claims with the National Flood Insurance Program since 1978, and were paid $380.4 million for buildings and contents, in the dollars of each year. The most came from Hurricane Katrina in 2005: 2,979 claims (49% of all) and $355.3 million, then Tropical Storm Isidore in 2002 with 683 and Hurricane Gustav in 2008 with 398. 83% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 133 Mississippi cities on this site with 10 or more claims, 132 have fewer than Bay St Louis.