The 2025 Atlantic hurricane season, commencing on June 1 and concluding on November 30, is expected to experience above-average activity. Colorado State University (CSU) predicts 17 named storms, with nine anticipated to become hurricanes and four reaching major hurricane status, classified as Category 3 or higher. This projection represents approximately 125% of the average observed from 1991 to 2020.
Anna Pergerson (Neely), Managing Director and Head of Catastrophe R&D at Howden Re, stated: “Our findings indicate a shift in El Niño–Southern Oscillation (ENSO) dynamics that increasingly support greater storm intensity and longevity. While ENSO phases remain a valuable indicator of seasonal hurricane activity, our data shows that actual losses are more closely influenced by storm tracks, landfall locations, and the level of community preparedness. For example, for the last three years in a row, Florida has experienced a major hurricane starting with Ian in 2022, but impacts to the Florida market varied widely from storm to storm.”
The heightened activity is partly due to unusually warm Atlantic Sea Surface Temperatures (SSTs), which provide essential energy for storm development and intensification. These warmer waters enable storms to grow stronger and sustain themselves longer.
Currently, ENSO is in a neutral phase and is expected to remain so throughout the season. Historically, this phase results in slightly lower but still elevated hurricane activity akin to La Niña conditions. Major forecasting groups such as the National Oceanic and Atmospheric Administration (NOAA), Tropical Storm Risk (TSR), and CSU agree that these conditions suggest increased activity.
Justin Roth, Associate Director of Catastrophe Analytics R&D at Howden Re, remarked: “This year, a persistently positive Atlantic Multidecadal Oscillation combined with a neutral-to-La Niña–like El Niño-Southern Oscillation (ENSO) pattern is expected to reduce vertical wind shear and promote storm development during the peak of the season. Although ENSO is currently neutral and forecasted to remain so, we still anticipate elevated though somewhat moderated hurricane activity.”
Notably, the European Centre for Medium-Range Weather Forecasts’ seasonal AI-enhanced model also indicates an active season ahead. This model performed exceptionally well in previous years like 2023 and 2024.
Several thermodynamic factors are aligning to support this above-average outlook. Anomalously warm tropical Atlantic SSTs exceeding the mean from 1981–2010 are likely to enhance heat and moisture fluxes into developing hurricanes. A consistently positive Atlantic Multidecadal Oscillation phase along with a projected neutral-to-La Niña-like ENSO phase should jointly suppress vertical wind shear while promoting cyclogenesis throughout the peak season.
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