This summer was the longest stretch of warm weather in the Twin Cities on record

The Twin Cities saw its longest recorded streak of days that reached 70 degrees or hotter this summer.

The 118-day stretch, from May 27 to Sept. 21, beat out the previous length of 107 days set in 2018, according to the National Weather Service office in Chanhassen.

The heat, along with dry conditions through the summer, could also dull autumn colors. The temperature streak may be less noticeable than scorching days in the summer, but it's part of a larger pattern.

"We're extending the summer into September longer than we used to," said Pete Boulay, a climatologist with the Minnesota Department of Natural Resources.

Climate change is pushing temperatures higher across the globe. So far, that has shown up in Minnesota in warmer, shorter winters.

That won't always be the case. According to the Fourth National Climate Assessment, "Warm-season temperatures are projected to increase more in the Midwest than any other region of the United States."

In the Twin Cities, most of these long stretches of highs above 70 have happened in the last 20 years, said Weather Service Meteorologist Jacob Beitlich.

Along with the unusually persistent warmth, this year also stands out for drought conditions that have lingered around the Twin Cities. The area is still in the severe drought category, according to the U.S. Drought Monitor.

2022 is on track to be the fourth-driest summer, based on rainfall between June 1 and Sept. 30.

It's unlikely that any significant rain will come through the end of the month. Only one computer model shows about five-hundredths of an inch falling in the next few days, which Beitlich called an almost "comical" amount.

In addition to contributing to a dry summer overall, the chances are that this will stand as the driest September since weather records in the Twin Cities began, in 1871. It would break a record for dry Septembers set in 1882, Boulay said.

The cumulative heat and dryness may also take a toll on fall color.

Val Cervenka, the forest health program coordinator with DNR, said leaves start to change color from the combination of cooler temperatures and shorter days. Persistent warmth while daylight wanes can muddle the leaf colors that emerge.

Drought is also a well-known factor in fall color, Cervenka said. If trees aren't getting enough water, their leaves may be duller or simply crumple and turn brown, rather than displaying brilliant reds and yellows.

In particular, the anthocyanins that create a scarlet canopy in some hardwoods aren't produced without cold nights, she said.

"As we stay warmer, the color just is not happening," Cervenka said. "If a tree is also respiring more because it's hot and the water is evaporating more quickly from the leaves, that's going to have an effect."