NOAA: oceans warmer than ever in September – fourth record month in a row
Sea surface temperatures were 1.10 °C above the 20th-century average – a record for any month. Globally, NOAA says it was the second-warmest September since 1850.
Symbolic image · Photo: Arturo Mann / Wikimedia Commons, CC BY-SA 3.0 (cropped and resized)
The US climate agency NOAA (National Centers for Environmental Information) released its global climate report for September on 9 October 2026. According to the report, global sea surface temperatures averaged 1.10 °C above the 20th-century average – the highest value for any month on record. September beat the previous record, set in August 2026, by 0.02 °C, making it the fourth consecutive month of record-warm oceans. These are measured data, not a projection.
Land and ocean combined were 1.33 °C above the 20th-century average – second place in the 1850–2026 record, just 0.07 °C behind September 2023. Land areas alone reached 1.83 °C above average, the third-highest September value in 177 years. For the Arctic, North America and Asia it was the warmest September on record, according to NOAA. The monthly report gives no uncertainty range; with such narrow margins to the record year, the ranking should be read with caution.
NOAA attributes the record warmth in the central and eastern tropical Pacific to persistent El Niño conditions. Global sea ice extent was the third-smallest for September in the 48-year record, NOAA says. January to September 2026 was the second-warmest such period after 2024. NOAA considers it "very likely" that 2026 will rank among the five warmest years, most likely second; the agency gives no percentages. Europe's Copernicus climate service had not yet published its September analysis as of Saturday.