Hurricanes and Tornadoes That Hit Chalmette, LA

The nearest NOAA station with 1991–2020 climate normals is Terrytown 3S, LA, 5 miles southwest of Chalmette at 10 feet. July and August are the warmest, with an average high of 92°F and low of 76°F; January is the coolest, at 63°F and 45°F. July is the wettest at 7.3 inches of precipitation on average and October the driest at 3.7 inches; the year adds up to 66.0 inches over 78 days with at least a tenth of an inch. June to November, the hurricane season months, bring 54% of the year's precipitation (35.7 of 66.0 inches); the other six months are drier. September has brought the most of the 79 tropical systems that passed within 75 miles (35); a normal September there has highs of 89°F and 6.8 inches of precipitation. Highs reach 90°F on about 90 days a year, almost all from May to October. Lows fall below freezing on about 7 nights a year. That 66.0 inches is more than at 74 of the 81 Louisiana stations used on this site (91%). Belle Chasse, 9 miles south, has its own station (New Orleans Alvin Callender Fl, LA): 64.1 inches a year, 1.9 less than here, and a July average high of 90°F against 92°F.

Water temperature at the NOAA tide station Carrollton, LA, 11 miles west, averaged 88°F in August and 47°F in February over 2021–2025. It averaged 80°F or warmer from June to September. Sea level at the New Canal tide gauge, 11 miles from Chalmette, has risen 2.36 ± 0.19 inches per decade from 1982 to 2025, NOAA's linear trend; at that pace it is 23.6 inches in a hundred years. That is faster than at 131 of the 144 U.S. gauges with a NOAA trend.

Since 1996, the National Weather Service has logged 409 flood, rain, thunderstorm wind and lightning events that began within 10 miles of Chalmette: 213 flash floods, 175 thunderstorm wind reports, 13 heavy rain events, 5 floods and 3 lightning strikes. They killed 1 person and injured 3, and the NWS estimated $1.6 million in property and crop damage. The strongest thunderstorm gust on record here was 100 mph, on March 29, 2011. July has had the most flash floods, 43 of 213. Of the 239 Louisiana cities on this site with a flash flood on record, 228 have had fewer than Chalmette.

Flood insurance policyholders in Chalmette's ZIP code 70043 have filed 12,005 claims with the National Flood Insurance Program since 1978, and were paid $1.16 billion for buildings and contents, in the dollars of each year. The most came from Hurricane Katrina in 2005: 8,202 claims (68% of all) and $1.13 billion, then Flooding in 1978 with 2,577 and Hurricane Rita in 2005 with 256. 96% of the claims carry the name of a storm or flood event; the rest have no event name. Of the 219 Louisiana cities on this site with 10 or more claims, 211 have fewer than Chalmette.