September 2026 Temperature data from the Copernicus Climate Change Service (C3S) show that September was the second-warmest September ever recorded globally. The average global surface air temperature reached 16.27°C, which was 0.82°C above the 1991–2020 average. It was also 1.63°C above the estimated pre-industrial level. The findings, released on 12 October 2026, highlight the continuing rise in global temperatures and the growing influence of climate change.

September 2026 Ranks as the Second-Warmest September

The Copernicus Climate Change Service is part of the European Union’s Earth observation programme and is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF). It uses the ERA5 climate dataset to track global temperature changes and other climate conditions.

September 2026 was 0.11°C cooler than September 2023, which remains the warmest September in the ERA5 record. The latest figures also show that September was the second consecutive month in 2026 when global temperatures were more than 1.5°C above the estimated pre-industrial average.

A single month above 1.5°C does not mean the long-term temperature goal of the Paris Agreement has been permanently crossed. That goal concerns global warming measured over a sustained period. However, repeated months at these levels show the scale of the current warming trend.

El Niño Adds to Global Temperature Concerns

El Niño is a natural climate pattern linked to warmer-than-usual sea surface temperatures in parts of the tropical Pacific Ocean. It changes atmospheric circulation and can influence weather patterns across many regions.

In September 2026, the Niño 3.4 region recorded a monthly sea surface temperature of 29.70°C, a record for the region. Copernicus reported that El Niño conditions were strengthening and were expected to intensify further in the coming months.

El Niño can contribute to higher global temperatures, although it is not the only factor behind long-term global warming. Human-caused greenhouse gas emissions remain the main driver of the long-term rise in global temperatures.

The combination of global warming and a strengthening El Niño could keep temperatures unusually high into 2027, according to the climate service’s assessment.

Ocean Temperatures Reach a September Record

The oceans are absorbing much of the additional heat trapped by greenhouse gases. This affects marine ecosystems, sea levels and weather systems.

In September 2026, the average sea surface temperature across oceans outside the polar regions, between 60°S and 60°N, reached 21.05°C. This was the highest September value in the record, exceeding the previous September record of 20.92°C set in 2023.

High ocean temperatures can place stress on marine life, increase the risk of coral bleaching and influence rainfall patterns. Warmer seas can also provide more energy and moisture for some storms, although the effects vary by region and weather system.

Europe Experiences Unusually Warm and Dry Conditions

Europe recorded its third-warmest September, with an average land temperature of 16.26°C. This was 1.54°C above the 1991–2020 average. Western Europe experienced especially warm conditions, with September matching its previous regional record.

Many parts of western, central and eastern Europe also faced dry weather. Low rainfall following a dry summer contributed to exceptionally low river flows in parts of the Rhine, Danube, Vistula and Garonne-Dordogne river systems.

Low river levels affected navigation, water supplies and agriculture in several areas. Although rainfall brought some local relief late in the month, dry conditions remained a concern in parts of the continent.

Antarctic Sea Ice Reaches a Low Winter Maximum

September is generally the period when Antarctic sea ice reaches its annual winter maximum. In 2026, the daily sea-ice extent around Antarctica reached its third-lowest winter maximum in the satellite record. The monthly extent was also the third-lowest for September, at around 6% below the 1991–2020 average.

Sea-ice extent measures the area of ocean covered by sea ice according to a defined concentration threshold. Changes in sea ice can affect marine habitats, ocean processes and the way sunlight is reflected back into space.

In the Arctic, the daily sea-ice extent reached its annual summer minimum, ranking as the 14th-lowest in the satellite record. The monthly Arctic extent was about 10% below average.

What the Latest Climate Data Mean

The September 2026 findings underline the importance of monitoring temperatures, oceans and polar ice together. These measurements help scientists understand how the climate is changing and identify risks to ecosystems and communities.

Reducing greenhouse gas emissions remains central to limiting long-term warming. Expanding clean energy, improving energy efficiency, protecting forests and preparing communities for heatwaves, droughts and floods can help reduce climate risks.

The Copernicus Climate Change Service continues to publish monthly climate updates using observational data and climate records. These reports help governments, researchers and the public track changes and understand the wider effects of a warming planet.