October 2026 was the hottest on record

October 2026 was the warmest October on record since global observations began. According to data from the Copernicus Climate Change Service (C3S), which is operated by the European Centre for Medium-Range Weather Forecasts (ECMWF), the average global surface air temperature reached 15.35 °C, which is 0.90 °C above the 1991–2020 average and 1.75 °C above pre-industrial levels (1850–1900).

This is the third month in a row that global temperatures have exceeded the critical 1.5 °C threshold. Based on an analysis of ERA5 data, scientists state with a probability of over 99 per cent that 2026 will be the second calendar year in history (after 2024) to officially exceed the 1.5 °C threshold above pre-industrial levels.

Record-breaking El Niño and abnormal ocean temperatures

One of the main factors behind the sharp rise in temperature was an El Niño event of unprecedented intensity in the tropical Pacific Ocean. In October, the average sea surface temperature outside the polar regions reached a record high for that month — 20.95 °C — breaking the previous record set in 2023.

The figures were particularly striking in the key El Niño 3.4 region, where the sea surface temperature anomaly reached a record high of 3.21 °C, surpassing the peak values of the strongest super-El-Niños of 1982–1983, 1997–1998 and 2015–2016. The additional heat from this natural phenomenon has compounded the overall global warming trend caused by human activity.

According to C3S, the four-year average global temperature for the period 2023–2026 is also certain to exceed 1.5 °C, which highlights the persistent and unprecedented nature of the current warming trend.

The situation in Europe: droughts in the east and floods in the west

For the European continent, October 2026 was the second warmest on record (surpassed only by October 2022), with an average temperature 1.49 °C above normal. The greatest temperature anomalies were observed in Fennoscandia and eastern Europe, whilst in the southern Balkans, Greece and western Turkey, temperatures were close to normal or slightly below normal.

The hydrological situation on the continent was characterised by contrasts:

• Critical river low-water conditions: extremely low water levels and low-flow conditions persisted in the basins of major rivers in Central and Eastern Europe, including the Danube, the Rhine and the Vistula.
• Increased aridity: a significant shortfall in rainfall and worsening drought conditions have been recorded in the south-west of the European part of the continent and in the Black Sea region.
• Heavy downpours and flooding: at the same time, the UK, Ireland, Spain, Greece and Turkey experienced devastating downpours, which caused localised flooding.

In addition, experts have recorded a sharp decline in sea ice extent: in the Arctic, it was 9 per cent below average (the 13th lowest figure in 48 years), and in the Antarctic, it was 9 per cent below average, marking the second-worst figure in satellite records since 2023.

Read more news on GreenPost.