‘Unprecedented’ ocean temperatures and extreme heat waves pop up around the globe

Summer officially begins in the Northern Hemisphere on June 21.
A summer sunrise over a grassy meadow.
Parts of the world are already baking under the summer sun. Deposit Photos

There’s only one day to go before the official start of summer in the Northern Hemisphere—but some parts of the planet are already feeling the heat. Ocean temperatures are about nine degrees above normal in parts of the United Kingdom and Ireland, while India and parts of the southern United States are baking under record breaking heat. Here’s what you need to know. 

[Related: Summer is off to an extreme start—here’s why.]

‘Unheard of’ marine heatwave

The waters off the coasts of the United Kingdom and Ireland are several degrees above normal, particularly in the North Sea and north Atlantic Ocean. Global sea surface temperatures in April and May hit an all time high for those months according to records dating back to 1850. June is also on track to hit record heat levels, with the water in some areas off the coast of England up to nine degrees Fahrenheit (5 degrees Celsius) above normal. According to the National Oceanic and Atmospheric Administration (NOAA), parts of the North Sea are in a category four marine heatwave, which is considered “extreme.”

“The extreme and unprecedented temperatures show the power of the combination of human-induced warming and natural climate variability like El Niño,” University of Bristol earth scientist Daniela Schmidt told The Guardian.  “While marine heatwaves are found in warmer seas like the Mediterranean, such anomalous temperatures in this part of the north Atlantic are unheard of. They have been linked to less dust from the Sahara but also the North Atlantic climate variability, which will need further understanding to unravel.”

This heat is putting marine organisms at risk, and events like this will only continue if carbon emissions are not dramatically cut, according to Schmidt.

Southern heatwave–and severe weather–in the US

Over the holiday weekend, heat indexes in parts of Texas soared above 120 degrees Fahrenheit, breaking records. More records are expected to fall this week as the power grid strains. Over 40 million people were affected by excessive heat warnings and heat advisories, from the border of Mexico and southwest Texas and eastward towards the border of southern Louisiana, and Mississippi. 

In addition to the heat, overnight tropical humidity will trap in heat and prevent the nighttime low temperatures from dipping below 80 degrees in some places. The heat is expected to continue through the rest of this week, according to the National Weather Service

All of this heat and humidity have fueled some June tornadoes. At least 17 tornadoes were reported over the weekend across Arkansas, Oklahoma, Texas, Mississippi, Alabama, Florida, Oregon, and Colorado. One person was killed and 18 others injured from the severe storms, including a reported tornado, in Jasper County, Mississippi. 

“I’ve seen more tornadoes than I can count. I’ve never seen the level of decimation to a town, as I’ve seen today,” Texas Governor Greg Abbott said at a news conference on Saturday, June 17 according to The Washington Post

[Related: World set to ‘temporarily’ breach major climate threshold in next five years.]

Deadly heat wave in northern India 

In India, roughly 170 people have died amid a sweltering heat wave affecting two of the country’s most populated states. Routine power outages and overwhelmed hospitals compound the already dangerous situation. 

Heat-related illnesses have killed at least 119 people in In the northern state of Uttar Pradesh. In neighboring Bihar, at least 47 people have died.

“So many people are dying from the heat that we are not getting a minute’s time to rest. On Sunday, I carried 26 dead bodies,” Jitendra Kumar Yadav, a hearse driver in Deoria town, 110 68 miles from Ballia, Uttar Pradesh, told The Associated Press.

These regions of the country are known for extreme heat during the summer, but temperatures have been consistently above normal. According to the Indian Meteorological Department, high temperatures in recent days have consistently reached 110 degrees Fahrenheit. 

A dire report from the United Nations’ World Meteorological Organization (WMO) released late in 2022, found that the past eight years were the hottest on record. Since 1993, the rate of sea level rise has doubled, with the past two and a half years alone accounting for 10 percent of the overall rise in sea level since satellite measurements began about three decades ago.