Global ocean temperatures hit a record June high as shrinking sea ice and above-average cyclone activity underscore continuing climate change.
June 2026 was the second-warmest June ever recorded globally, while the world’s oceans reached their highest June surface temperatures on record, according to a new report released by the U.S. National Oceanic and Atmospheric Administration (NOAA).
The analysis, published on Thursday by NOAA’s National Centers for Environmental Information (NCEI), also found that Arctic and Antarctic sea ice continued to decline, with both regions recording June sea ice extents among the 10 lowest in the satellite record. Global tropical cyclone activity during the month was also above average.
Second-hottest June on record
According to NOAA, the global surface temperature in June 2026 was 1.09 degrees Celsius above the 20th-century average, making it the second-warmest June since global records began, behind only June 2024.
The report noted that warmer-than-average conditions prevailed across much of the world, with several continents and regions experiencing one of their 10 warmest Junes on record.
Oceans reach new June temperature record
Global ocean surface temperatures also set a new record for the month of June, reflecting the continued warming of the world’s oceans.
Scientists regard ocean temperatures as a key indicator of climate change because oceans absorb much of the excess heat generated by rising greenhouse gas concentrations and play a critical role in regulating the Earth’s climate system.
Sea ice continues to decline
The report showed that global sea ice extent fell to the fourth-smallest June coverage in the 48-year satellite record.
During the month, sea ice covered approximately 22.7 million square kilometres, around 2.02 million square kilometres below the 1991–2020 average.
Both the Arctic and Antarctic recorded June sea ice extents among the 10 lowest observed since satellite monitoring began.
2026 on course to rank among warmest years
Looking at the first six months of the year, NOAA said the January–June 2026 global surface temperature ranked as the third-highest on record.
Based on its Global Annual Temperature Outlook, the agency said it is very likely that 2026 will finish among the five warmest years ever recorded.
The findings add to growing scientific evidence of a long-term warming trend driven by climate change, with rising global temperatures continuing to influence weather patterns, ocean conditions and polar ice coverage around the world.