NOAA says September ocean temperature departure from average set all-time record for any month

ASHEVILLE, N.C. — Global ocean surface temperatures in September 2026 were 1.98°F (1.10°C) above average, the highest departure for any month on record, the National Oceanic and Atmospheric Administration's National Centers for Environmental Information (NCEI) said in its monthly global climate report.

The ocean figure topped the previous all-time record, set in August 2026, by 0.04°F (0.02°C). It was the fourth consecutive month in which the global ocean surface temperature departure set a new record high, NCEI said. The agency said persistent El Niño conditions drove record warmth across the central and eastern tropical Pacific.

Globally, September 2026 was 2.39°F (1.33°C) above the 20th-century average, making it the second-warmest September in the 1850–2026 record, behind 2023, according to the report. NCEI said the January–September global surface temperature was the second highest on record, behind 2024, and that it is very likely 2026 will rank among the five warmest years on record.