Weather tracker: Mediterranean Sea hit by major marine heatwave | Paraguay

Many parts of Europe have seen record-breaking temperatures over the past few months, but it is not just the continental landmass which has been affected. The Mediterranean Sea is experiencing a major marine heatwave, with sea surface temperatures in western parts of the Mediterranean 4-5C warmer than average. Temperatures have been above average for prolonged periods since the start of May, with June the warmest on record for large portions of the Mediterranean basin. The US National Oceanic and Atmospheric Administration (NOAA) has classified the current event as a “severe” category 3 event, one level from extreme thresholds.

Marine heatwaves can have devastating impacts on marine ecosystems and are expected to increase in intensity and frequency in the future due to human-induced climate change. Scientists have found that marine heatwaves between 2015 and 2019 in the Mediterranean caused mass casualties in marine species, coral bleaching and harmful algal blooms.

Elsewhere, a winter heatwave has been affecting parts of South America. Paraguay observed its hottest July day on record with 39.1C recorded at Vallemi airport on 25 July. The previous national July record was 38.5C. It has also been very warm in northern parts of Argentina, with 36.5C recorded in Las Lomitas on 26 July.

Meanwhile, a devastating wildfire has been raging in Mariposa County, California, close to Yosemite national park, home to some of the oldest sequoia trees on Earth. The Oak fire, which started on 22 July, has destroyed almost 19,000 acres of land and forced the evacuation of at least 6,000 people. Firefighters have made some progress over recent days and as of Thursday the fire was 39% contained. The wildfire was able to spread at ferocious speeds as a result of the tinder dry-ground thanks to months of drought.

The US Pacific north-west and western Canada is experiencing heatwave conditions which are not expected to ease until later this weekend. A temperature of 42C was recorded in Lytton, British Columbia on 27 July, the same location famed for smashing the Canadian temperature record in 2021. A temperature of 30.4C was recorded on the same date in Vancouver. Oregon’s governor has also declared a state of emergency due to the longevity of the high temperatures, with a high of 38.9C reported in Portland on 26 July. In Seattle, temperatures hit 34.4C.