The government said Friday this has been the hottest summer for Vancouver in 124 years of record-keeping, but the reason may surprise you.
Average daytime highs from June 22 to Aug. 14 have stayed around 82 degrees, which is actually normal for this time of year. And it hasn’t even reached 100 degrees yet.
The difference is that overnight low temperatures have been unusually high, skewing the data, said Matthew Cullen, a meteorologist with the National Weather Service’s Portland office.
“We’re just not dropping off and getting that overnight recovery period,” Cullen said. “We’ve had several nights where those lows really haven’t been dropping off as much.”
Those too-hot-to-sleep nights have driven Vancouver’s average daily temperature for this summer up to 70.8 degrees. The previous record was 70.5 degrees, set in 1906 and tied in 2004. The average daily temperature takes into account both the daily high and low.
On average, temperatures drop to 57 degrees overnight in August and tend to be even a little cooler in June and July, Cullen said. But the average low for this summer is 58.9 degrees.
From June 28 to Aug. 14, Vancouver had 28 days with low temperatures in the 60s, Cullen said. Monday tied July 1 for the hottest day of the summer, at 98 degrees. It was also the hottest night of the summer, with the temperature dropping only to 68 degrees.
It’s hard to pinpoint the cause of our hot summer nights, but Cullen points to a couple of factors. This summer, Vancouver has had more overnight cloud cover than usual, keeping the heat in. The area also hasn’t received as much cooling offshore airflow from the coast.
“It does happen from time to time,” Cullen said. “It’s just part of the natural cycle.”
Since 2003, Vancouver has posted four of its five warmest daily average summer temperatures. The city’s records go back to 1890.
Vancouver isn’t the only city in the region setting new records for average daily temperatures this summer. In Oregon, Portland, Salem and McMinnville have set records as well, and Eugene tied its record from the summer of 1990 at 70.2 degrees.
