In South Asia, a prolonged heat wave in Bangladesh triggered a power crisis, as temperatures exceeded 104 F (40 C) over multiple days.

In the United States, Texas is bracing for high humidity and triple-digit temperatures this week. Dangerously hot conditions are forecast across much of the state, including in Dallas, Austin, San Antonio and Houston.

“Near record to record heat remains in the forecast throughout the week across south-central Texas, with the hottest days likely coming Thursday and Friday,” the National Weather Service tweeted Monday. “It will be important to plan ahead to stay cool during these dangerously hot conditions.”

Meanwhile, the world’s oceans are not faring much better.

Sea surface temperatures around the globe have been at record or near-record highs over the past three months. The surge in global ocean temperatures — particularly over such a short period of time — is unprecedented, said Glen Gawarkiewicz, an associate scientist in physical oceanography at the Woods Hole Oceanographic Institution in Massachusetts.

“The rapid warming in the spring was on such a massive scale,” he said, adding that it will take some time for scientists to understand what is driving the spike in temperatures. “It’s very tough because we just haven’t seen a jump of that magnitude over such a large area before.”

Scientists closely monitor sea surface temperatures because warmer oceans can accelerate sea-level rise and intensify storms and extreme weather. But even small changes can have wide-ranging consequences for marine ecosystems.

Gawarkiewicz’s own research focuses on the Gulf of Maine, a region that is particularly sensitive to changes in temperature, salinity and other effects of climate change.

“I work very closely with the commercial fishing industry in the Northeast, and it is is very distressing to hear about, for example, the seasonal movements of fish being very strongly affected,” he said. 

Elsewhere around the world, warmer sea surface temperatures can supercharge tropical cyclones, wreak havoc on marine environments and cause polar ice to melt at an accelerated pace.

With the return of El Niño, a naturally occurring climate pattern, there is no end in sight to the warming trend.

El Niño occurs when changes in the strength or direction of trade winds cause waters in the central and eastern tropical Pacific Ocean to become warmer than usual. These shifts have a strong influence on global temperatures, rainfall, hurricanes and other severe storm systems.

Gawarkiewicz said that could mean more heat waves and droughts around the world, along with the potential for “major disruptions” to marine ecosystems, such as coral bleaching events.

“I think that the consequences may very well be severe,” he said.