COPERNICUS REPORTS NEAR-RECORD SEA TEMPERATURES IN WARM APRIL

Figure 1. Anomalies and extremes in sea surface temperature for April 2026. Colour categories refer to the percentiles of the temperature distributions for the 1991–2020 reference period. The extreme (“Coolest” and “Warmest”) categories are based on April rankings for the period 1979–2026. Values are calculated only for the ice–free oceans. Areas covered with sea ice and ice shelves in April 2026 are shown in light grey. Data source: ERA5. Credit: C3S/ECMWF.

With El Niño conditions expected to develop in the coming months, April 2026 saw the second highest sea surface temperatures on record for the extra–polar oceans, with record high temperatures across large parts of the tropical Pacific associated with strong marine heatwaves. The month was also the joint third–warmest April on record globally, according to the Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium–Range Weather Forecasts (ECMWF).

Figure 2. Daily sea surface temperature (°C) averaged over the extra–polar global ocean (60°S–60°N) for 2023 (yellow), 2024 (orange), 2025 (red) and 2026 (dark red). All other years between 1979 and 2022 are shown with grey lines. The daily average for the 1991–2020 reference period is shown with a dashed grey line.

Data source: ERA5. Credit: C3S/ECMWF.

There were significant contrasts in temperature anomalies across the Northern Hemisphere in April, although these were less pronounced than earlier this year. Europe saw strong regional differences, with much of southwestern Europe experiencing much warmer than average conditions and Spain seeing its warmest April on record, while colder than average conditions were seen in eastern Europe. As a result, April 2026 ended as the tenth warmest month on record for the continent, with this ranking masking these regional contrasts. In the Arctic, the sea ice extent was the second lowest for April, remaining close to record lows for the time of year, as it has been since the beginning of the year.

The month was also marked by extreme weather events, including tropical cyclones in the Pacific, floods in the Middle East and south–central Asia, and droughts impacting southern Africa. Flash flooding hit much of the Arabian Peninsula, while parts of Iran, Afghanistan, Saudi Arabia and Syria experienced widespread flooding and landslides, claiming lives.

Samantha Burgess, Strategic Lead for Climate at ECMWF, commented: “April 2026 adds to the clear signal of sustained global warmth. Sea surface temperatures were near record levels with widespread marine heatwaves, Arctic sea ice remained well below average, and Europe saw sharp contrasts in temperature and rainfall; all hallmarks of a climate increasingly shaped by extremes.”

Figure 3. Surface air temperature anomaly for April 2026 relative to the April average for the period 1991–2020.

Data source: ERA5. Credit: C3S/ECMWF.

April 2026 – Surface air temperature and sea surface temperature highlights

Global temperature

• April 2026 was the joint third–warmest April globally, with an average surface air temperature of 14.89°C, 0.52°C above the 1991–2020 average for April, according to the ERA5 dataset. The warmest April on record was in 2024 and the second warmest was in 2025.
• April 2026 was 1.43°C above the estimated 1850–1900 average used to define the pre–industrial level.

Europe 

• The average temperature over European land for April 2026 was the tenth warmest at 8.88°C, 0.50°C above the 1991–2020 average for April. The warmest April on record was in 2018.
• Temperature anomalies across Europe were marked by sharp regional contrasts, with much warmer than average conditions over southwestern Europe and colder–than–average conditions over much of eastern Europe.

Sea surface temperature

• Throughout April, the daily average SST over the extra–polar global ocean (60°S–60°N) gradually inched toward the record values observed in 2024, reflecting the transition from ENSO–neutral towards El Niño conditions now expected in the coming months.
• The average sea surface temperature (SST) for April 2026 over 60°S–60°N was the second–highest value on record for the month, at 21.00°C. The highest April SST on record occurred in 2024 during the last El Niño event.
• SSTs reached record highs for the month across a broad region from the central equatorial Pacific to the western coast of the United States and Mexico, corresponding to ‘strong’ marine heatwave conditions.

April 2026 – Hydrological variables highlights

• April 2026 was predominantly drier than average in western and central Europe, due to a persistent high–pressure area over the region.
• Conversely, much of easternmost and southeastern Europe, along with Iceland, the UK and Ireland, parts of Spain and Italy, the Maghreb coast, and the Caucasus, saw above‑average precipitation and soil moisture.
• Outside Europe, wetter–than–average regions in April 2026 included the northeastern and central United States, Canada, northern Mexico, the Arabian Peninsula and Afghanistan, southern China, Japan, parts of Brazil, southern Africa, and New Zealand. In contrast, drier‑than‑average conditions prevailed in the southeastern United States, Central Asia, Madagascar, Australia, and parts of South America.

April 2026 – Sea ice highlights

• In the Arctic, the average sea ice extent in April was about 5% below average, ranking the second lowest for the month, slightly less than the April record set in 2019 (6% below average).
• Regionally, sea ice cover was most below average in the Sea of Okhotsk and in the northern Barents Sea and the Svalbard region, as already seen in March.
• In the Antarctic, the monthly sea ice extent was about 10% below the April average, ranking the 11th lowest for the month, and close to values observed in the past two years.
• Sea ice cover was much below average in the Bellingshausen Sea, which remained virtually ice–free, while it was above average in the neighbouring Amundsen Sea.