A retrospective on the 2025 Atlantic hurricane season

Abstract

Tropical cyclone activity was intermittent during the 2025 Atlantic season, with extended quiet periods. Cumulative activity was near-average relative to 1991-present, despite warm sea-surface temperatures and La Nina conditions. We compare drivers of activity in 2025 with climatology, using reanalysis data to examine variability in environmental conditions, wave activity, and circulation patterns. During the early and peak season, high pressure, a strong upper-level trough and cool equatorial sea-surface temperatures led to weak seed disturbances and unfavourable development conditions. Stronger disturbances coinciding with Kelvin wave activity and favourable MJO conditions led to a more active late season.