GRAND FORKS - The official numbers are saying what gardeners have known for weeks - this area saw its coolest summer on record. The area's warmest temperatures of the year were reported Thursday - at the start of September.

The National Weather Service said Fargo hit 92 degrees Thursday and Grand Forks hit 90, both high temperatures for the year.

In contrast,the average daily temperature for June, July and August in Grand Forks was a record 61.8 degrees, or 0.7 degree cooler than the previous record, set in 1968, for that three-month period.

"It's been generally cold all summer. As you go north, the magnitude increases," said John Enz, the North Dakota State University Extension Service climatologist.

August in the Red River Valley this year was nearly 10 degrees below normal.

"Across the northern part of the state - even the central, 7 to 10 degrees below normal is not uncommon," Enz said.

Average temperatures in July generally were about 4 degrees below normal for the entire state, while June temperatures were coldest in western North Dakota.

In June, the average temperature in Williston was 59 degrees, several degrees below normal, Enz said.

Bismarck's average temperature for June, July and August was 65.4 degrees - tied for the 17th coolest with the summers of 1892, 1903 and 1905.

"Our coolest summer ever was 62 degrees, and that was in 1915," said meteorologist Todd Hamilton, of the weather service in Bismarck.

In Minnesota, "International Falls will have its coldest summer on record, June through August," said Pete Boulay, assistant Minnesota state climatologist. "The Twin Cities will finish at about the seventh-coldest August."

Temperatures in Crookston, Minn., averaged 60.2 degrees in August, or 7.9 degrees below normal, Boulay said. That's the coldest August since record keeping began in 1890, he said.

Although the northern Plains and Montana may have had some of the coolest temperatures, states farther south such as Kansas also had their share of cool days because of the way the jet stream was situated this summer, forecasters said.

"There's (been) a persistent northwest flow of air for the entire summer," said Bill Barrett, a National Weather Service meteorological technician in Grand Forks. Although the jet stream has pushed north over Canada this week, allowing warm air into the region, it is expected to move south again next week.

"It will affect the Dakotas with some below-normal seasonal temperatures for next week," Barrett said.

The U.S. Climate Prediction Center's 30-day outlook is for below-normal temperatures and above-normal precipitation for most of North Dakota and Minnesota. The center's 90-day outlook for October through December says the chances of having above-normal or below-normal temperature are about equal.