Following one of the hottest summers on record, the fall looks to be exceptionally toasty as well. The National Oceanic and Atmospheric Administration’s fall outlook calls for above average temperatures across the entire Lower 48 and Alaska.
The areas with the highest likelihood of warmer-than-average conditions this fall include Alaska’s North Slope, the Four Corners region and New England. Ordinarily, sea ice would chill the North Slope. But not this year.
“The overall retreat in the Beaufort Sea is about as extreme as our analyses have shown in the last 20 years,” wrote the National Weather Service in Anchorage. Utqiaġvik — Alaska’s northernmost town — spent 85 days above freezing, from June 25 to Thursday.
“Prior to the 1990s it wasn’t uncommon for the longest above freezing streak to be (less than) 10 days,” tweeted Rick Thoman, an Alaska climate specialist at the International Arctic Research Center. Satellite-derived Arctic sea ice extent this season reached its second-lowest on record, behind only 2012.
This fall should prove no different.
It's no surprise that this comes on the heels of an exceptionally warm summer, during which not a single state ranked below average.
July was the planet's warmest month on record while the summer overall ranked as the hottest on record for the Northern Hemisphere. The past five years have marked the warmest period on record as well.
And yet despite this, much of the U.S. hasn't been as toasty as it might be due to a stubborn dip in the jet stream over the Plains and northern tier.
Summer in the contiguous United States was the coolest in five years, but cool is relative — it was still anomalously hot compared to long-term baselines, and summer ranked in the top third of such seasons historically, NOAA found. The Central U.S. cooldown prevented the D.C. area from ending up higher on the leader board. But a number of other locations logged some mind-boggling heat.
Take Alaska, for instance. Anchorage recorded eight 80-degree days this year. The previous record is four times in a season. The overnight low failed to drop below 60 degrees nine times. That’s as many times in three months as occurred between 1950 and 1990. This summer was 12% more humid in Alaska’s largest city than during any other summer on record.
Hawaii is in the same boat, thanks to anomalously high sea surface temperatures surrounding the islands. Honolulu saw its warmest summer on record. So did Kahului and Lihue, two of Hawaii’s other three long-running climate stations. The only Aloha State station to miss the mark was in Hilo, where 2019 came in second place behind 2015. Four of the top five warmest summers on record there have occurred in the past five years.
Lihue, on the island of Kauai, broke or tied its record high temperature 20 days in a row. Bob Henson, a meteorologist at Weather Underground, described the remarkable feat as “likely unprecedented.” Twenty-seven of the last 32 days have featured record-tying or -breaking temperatures for the station, at which records date back to 1905. That means if you were to select a random day during the past two months, there’s a roughly two out of three chance of it being a record setter.
Lihue also has seen 41 record high minimum temperatures since the beginning of July. For comparison, Lihue has measured exactly zero record lows during 2019.
Hawaii’s not the only tropical paradise baking. Miami is feeling the heat, too. Temperatures didn’t drop below 80 degrees for nine days in a row, ending Sept. 11. They also saw a four-day stretch of temperatures topping 95 degrees back in June. Miami has hit 90 or greater every day this month except Thursday. Brian McNoldy, Capital Weather Gang’s tropical weather expert, pointed out that it’s been the warmest front-half of September on record in Miami.
Just about everybody's been hot outside that trough that chilled the nation's Heartland. Even New England saw an exceptionally hot summer. July was the warmest month on record in Boston, Portland, Hartford and Manchester. Sure, there's been cold in some spots. But there's been a heck of a lot more warmth.
And it looks like that trend is set to continue. The majority of weather models depict a warmer-than-average pattern as we head into winter. A chunk of average or slightly below average temperatures may become briefly nestled over New England, but otherwise warmth is favored virtually everywhere.