Georgia’s weather swings from wet winters to dry ones, and from quiet hurricane seasons to active ones. Two weather patterns thousands of miles away in the Pacific Ocean control much of this change.
What’s Happening: El Niño and La Niña are opposite weather patterns that happen when ocean temperatures in the Pacific Ocean near the equator change. Trade winds normally blow warm water from South America toward Asia. When those winds weaken, warm water pushes back east, creating El Niño. When the winds get stronger than normal, they push even more warm water west and bring cold water up from the deep ocean, creating La Niña.
What’s Important: These patterns shift the jet stream that guides storms across the United States. That means Georgia gets different weather depending on which pattern is active. Each pattern typically lasts nine to 12 months, but some last for years. They happen every two to seven years on average.
What the Names Mean: Spanish-speaking fishermen off the coast of South America noticed unusually warm water appearing around Christmas in the 1600s. They called it El Niño, which means “the little boy” in Spanish, referring to the Christ child. Scientists later named the opposite cooling pattern La Niña, meaning “the little girl.”
El Niño Brings Wet, Cool Winters to Georgia: During El Niño winters, the southern half of the United States including Georgia typically sees more rain and cooler temperatures than normal. The Pacific jet stream shifts south, bringing more storm systems across the state. Atlanta recorded its warmest December on record in 2015 during a strong El Niño, and 2015 was Atlanta’s third wettest year on record. Strong El Niño winters have brought major winter storms to Georgia, including the snowiest winter on record for Columbus and Macon in 1972-73 and a crippling ice storm in Atlanta in January 1973. The March 1998 Gainesville tornado during El Niño killed 12 people.
El Niño Quiets Hurricane Season: El Niño typically reduces Atlantic hurricane activity. Records show that since the 1960s, only three of 14 El Niño seasons had average or above-average tropical storms and hurricanes. The pattern increases wind shear in the atmosphere that tears apart developing storms. Despite fewer storms overall, Georgia has still felt effects from tropical storms or depressions 50 percent of the time during El Niño years.
La Niña Brings Warmer, Drier Winters: During La Niña, Georgia typically sees warmer and drier conditions than normal, especially in southern parts of the state. Trade winds strengthen and push the jet stream north, keeping storm tracks away from Georgia. This can worsen drought conditions. Cities like Rome, Georgia saw temperatures 5.6 degrees warmer than average during the La Niña winter of 2021-22.
La Niña Increases Hurricane Risk: La Niña weakens wind shear over the Caribbean Sea and Atlantic Ocean, allowing more hurricanes to develop and strengthen. Six of the most active Atlantic hurricane seasons on record occurred during La Niña conditions, including the record-breaking 2020 season with 30 named storms and 2005 with Hurricane Katrina. The pattern increases hurricane landfall activity from Georgia northward along the East Coast. Between 1900 and 1998, only five hurricanes made landfall in Georgia, with four hitting during neutral years and one during El Niño. No hurricane has ever made landfall in Georgia during La Niña, though the state faces increased risk from storms that develop.
Between the Lines: Scientists measure these patterns using ocean temperatures in the Pacific. El Niño conditions exist when temperatures are at least 0.5 degrees Celsius above normal for at least five consecutive months. La Niña requires temperatures at least 0.5 degrees Celsius below normal for the same period. When temperatures fall between these ranges, conditions are neutral. Scientists call the complete cycle the El Niño-Southern Oscillation, or ENSO.
The Big Picture: El Niño and La Niña affect weather across the entire planet, not just Georgia. During La Niña, the northern United States typically sees more snow and colder temperatures while the South stays warm and dry. During El Niño, the pattern reverses. These ocean temperature changes in the Pacific influence everything from droughts in Australia to flooding in South America. While scientists can predict the development of El Niño or La Niña several months to a year in advance, they cannot predict specific storms or weather events. The patterns only increase the likelihood of certain conditions.
The Sources: National Oceanic and Atmospheric Administration, National Weather Service, Climate Prediction Center, and Florida State University Climate Center.
B.T. Clark
B.T. Clark is an award-winning journalist and the Publisher of The Georgia Sun. He has 25 years of experience in journalism and served as Managing Editor of Neighbor Newspapers in metro Atlanta for 15 years and Digital Director at Times-Journal Inc. for 8 years. His work has appeared in several newspapers throughout the state including Neighbor Newspapers, The Cherokee Tribune and The Marietta Daily Journal. He is a Georgia native and a fifth-generation Georgian.
