October 2026 was the hottest October on record globally, with temperatures 1.75°C above pre-industrial levels, according to the Copernicus Climate Change Service (C3S).
Global temperatures exceeded the 1.5°C threshold for the third consecutive month, and 2026 is on course to become the second-warmest year on record. The global average surface air temperature in October was 15.35°C, which was 0.9°C above the 1991-2020 average. The four-year global temperature average for 2023–2026 is also expected to exceed 1.5°C above pre-industrial levels.
An exceptionally strong El Niño contributed to record ocean temperatures. The average sea surface temperature in oceans outside polar regions reached 20.95°C in October 2026, the highest on record for the month. The Niño 3.4 region recorded a record anomaly of 3.21°C, exceeding previous strong El Niño events.
Source: Down To Earth