Copernicus Marine Service closed April 2026 as the second-warmest April on record for the global ocean — mean sea surface temperature 21.08°C, only 0.02°C below April 2024's record. The equatorial Pacific hit 26.99°C, the warmest April there ever recorded, surpassing 2017's 26.86°C. The Mediterranean ranked fourth-warmest. The North Atlantic ranked third-warmest. Around 8 percent of the global ocean ranked as the warmest April ever; more than half ranked within the ten warmest. [1] Yesterday's paper carried the climate prints framed against the preseason hurricane forecasts disagreeing by a factor of two. Today the calendar tightens.

April 2026 was the third-most-extreme April month for the global ocean in marine-heatwave intensity, after 2023 and 2024. The Mediterranean ranked fourth-most-extreme for MHW intensity. Carlo Buontempo, director of the Copernicus Climate Change Service, framed the climate-system print directly: 1.48°C above pre-industrial, the lowest Arctic sea ice extent on record for March, sea-surface temperatures again approaching historic highs. [2] Many climate centers, including ECMWF, are forecasting transition from neutral to El Niño in the second half of 2026.

The hurricane-season prep begins now. Atlantic season opens June 1 — twenty-six days. The National Hurricane Center coordinates with FEMA and Atlantic-basin coastal states from this week forward; NHC will issue inland tropical-storm and hurricane watches and warnings using cones extending further inland than in prior years, in response to the freshwater-flooding deaths that dominated Helene's 2024 toll. The preseason forecast spread is the planning signal. Colorado State calls for thirteen named storms, six hurricanes, two majors. North Carolina State predicts twelve to fifteen, six to nine, two to three. The University of Arizona's April 3 model produces twenty named storms, nine hurricanes, four majors. [3] CSU bets the El Niño shear wins. Arizona bets the warm-ocean fuel does. NCSU hedges. None of them are forecasting the same season. The cones get drawn against an ocean that has spent the spring at near-record heat and an ENSO state still in transition. The first cone with the new inland protocol arrives in real time.

-- DARA OSEI, London