Temperatures are already breaking records this year: Last month was the warmest May for the world’s oceans since records began in 1850, according to the National Oceanic and Atmospheric Administration.
The average ocean temperature during May was 1.53 degrees Fahrenheit, or 0.85 degrees Celsius, above normal for the month.
For the planet as a whole, May was the third warmest on record, the agency said Thursday in its monthly climate update. North and South America experienced the warmest May on record.
In the United States, rising temperatures have hit Washington state and northern Idaho particularly hard. Two Washington cities, Bellingham and Spokane, as well as smaller communities in the region, set records for their warmest Mays.
Why it matters: Heat can harm ocean life and fuel wildfires.
Warmer water tends to hold less oxygen and large fish kills may occur earlier in the year as the climate continues to warm. Last week, thousands of dead fish washed up on Texas beaches from the unusually warm waters and lack of oxygen in the Gulf of Mexico. On the other side of the ocean, warmer temperatures are contributing to the death of coral reefs. The ocean also expands as it warms, raising sea levels even more on top of the added water from the melting ice sheets.
Unusual heat last month contributed to a spate of wildfires in Canada. As smoke from wildfires spread, air quality in western Canada and the northern Great Plains of the United States deteriorated significantly. Recently, smoke from wildfires has reached cities in the Northeast and Midwest, causing air quality index results skyrocket in much of the country.
Extreme heat it can be dangerous to both humans and wildlife. Over the next few days, parts of Florida, Louisiana and Texas are bracing for possible triple-digit temperatures that put people at risk, especially if they work outside or don’t have air conditioning.
Background: El Niño joins climate change.
“With climate change and global warming, it’s been an interesting start to the season,” Rocky Bilotta, NOAA climatologist, said on a call with reporters.
Last week, the agency said the global ocean and atmosphere had officially entered a climate pattern known as El Nino, which occurs naturally when the surface of the Pacific Ocean becomes warmer than usual. The phenomenon generally leads to warmer temperatures globally, but Mr Bilotta said El Niño was most likely to affect temperatures later this year and next.
It’s hard to pin down a single cause of May’s heat wave, he said, but as the climate warms overall, more and more temperatures and records can be expected worldwide, both in the ocean and on land.
What will be next: Likely year of extreme weather.
Most of the United States can expect an unusually hot summer with an increased risk of drought and wildfires, according to NOAA. South Texas and much of New England is in for a particularly hot July. On warmer days, plants lose more water to the atmosphere and dry out, exacerbating the effects of drought and providing more fuel for fires.
Warmer temperatures can also lead to more evaporation from the ocean and other bodies of water. More water vapor in the atmosphere can then lead to heavier rain and snow and fuel tropical storms.
Next month, the northern Great Plains, Mid-Atlantic region and western Gulf Coast can expect more than normal precipitation, the agency predicts. Throughout the summer, the central part of the country can expect more rain, while the Pacific Northwest, parts of the Southwest, the Great Lakes region and parts of the mid-Atlantic should prepare for dryness.
Longer term, El Niño conditions will almost certainly last through at least the spring of 2024 and could contribute to worse winter storms in the southern United States.