Since 1950, when El Niño recordkeeping began, snow or sleet has been observed in Baton Rouge approximately 51 times. The majority of those wintry weather events did not coincide with an active climate phase: 40% of all observations occurred during neutral periods when neither El Niño nor La Niña was present.

When comparing the two active patterns directly, El Niño is more likely to generate wintry precipitation than La Niña. Roughly 35% of snow or sleet observations in the capital city took place during an El Niño winter.

Freeze counts tell a similarly nuanced story across southern Louisiana. The Baton Rouge area experiences freezing temperatures around 20 times per year, with a typical variance of plus or minus eight freezes per season.

The all-time record of 37 freezes in a season was set during the El Niño winter of 1977. Despite that individual record, La Niña winters hold more spots than El Niño in the top 20 rankings for total winter freeze counts.

The parity between the two patterns comes down to fundamental differences in atmospheric dynamics. During an El Niño winter, an active subtropical storm track sets up over the capital region, producing persistently wet weather that holds daytime temperatures down under dense cloud cover and rain.

By contrast, while La Niña winters tend to be warmer and drier on average, they often cause the jet stream to buckle sharply from north to south. Those dramatic ripples in the storm track allow brief but intense blasts of Arctic air to plunge deep into the South, creating short windows for freezing temperatures and winter precipitation.