For the first time on record, every square inch of all 50 states is forecast to see above-average temperatures for the next three months, according to a forecast map from the federal government’s Climate Prediction Center.
An entire forecast map awash in the red and orange colors of unusually warm temperatures for a 3-month period is unprecedented, according to Dan Collins, a meteorologist with the prediction center. Typically parts of the map register blue, depicting the likelihood of cooler-than-normal air, or white for equal chances of cool and warm.
The archives for the center’s climate predictions go back to 1995, Collins said.
A separate climate prediction from the Weather Company for August to September shows a very similar warmer-than-normal forecast for practically the entire nation, with summer-like temperatures expected to continue into the early fall for many U.S. locations. The Weather Company, the parent company of the Weather Channel, predicts heat relief for just one part of one state: northern Montana.
Collins attributes the persistent heat to unusually warm ocean temperatures, which will keep the atmosphere over the U.S. warm over the next few months. Additionally, he said the warmer U.S. temperatures during this decade, when compared to what was “normal” in past decades, increase the chance of U.S. warmth in late summer and early fall.
Man-made climate change may also be a factor. Scientists have found links between extreme heat waves and climate change, a report earlier this year from the National Academies of Sciences, Engineering and Medicine said.
The ongoing heat is due to a “blocking” pattern in the upper atmosphere that allows high-pressure ridges to build. Air sinks under high pressure, preventing clouds and rain from forming.
Todd Crawford, chief meteorologist with the Weather Company, said that these types of blocking patterns during the summer months have been more common in recent years, and it may be related to a sharp decline in Arctic sea ice due to climate change.
June was record warm both in the U.S. and around the world, and 2016 is on course to be the Earth’s warmest year on record. June was the warmest non-July since records began in 1880, NOAA said. All of the planet’s 11 hottest months on record were in July.
If July turns out to be a record, it will be the warmest of the past 1,627 months, or since global records began in January 1880.