Above-average sea surface temperatures across European seas at the end of June 2026

Sargassum blooms are seasonal accumulations of floating algae which can occur across the Caribbean Sea. This bloom has been larger than usual between April and June 2026, raising concern because of the impact this has on tourism, fisheries, and coastal communities.

The Bijagós Archipelago, a system of 88 islands off the coast of Guinea-Bissau in West Africa, has been designated by UNESCO as the Bolama-Bijagós Biosphere Reserve. Its mangroves and surrounding waters support rich birdlife, fish, reptiles, mammals, and important green sea turtle nesting sites are highly sensitive to environmental change.

Between 23 and 25 June 2026, a broad area of clear weather brought blue skies across much of the United Kingdom and Ireland, providing us with an unusually cloudless view of the landscape from space. Such weather is relatively uncommon across these islands, where Atlantic weather systems frequently bring extensive cloud cover.

During the summer months, large algal blooms occur frequently in the Balic Sea. Often driven by warmer temperatures, abundant sunlight, and nutrient-rich waters, these blooms can reduce water quality and affect marine life. In late June 2026, a new algal bloom was observed across parts of the Baltic Sea.

Western and Central Europe are facing a severe heatwave caused by a persistent high-pressure atmospheric system known as an “Omega block”.