The thermometer hit the century mark at 4:55 p.m. Thursday, just shy of the all-time high reached for the day in 1995, according to the National Weather Service's Medford office.
Reaching 100 degrees in September is not that unusual for the Rogue Valley, although it has never been recorded after Sept. 27.
Chuck Glaser, data acquisition program manager for the weather service, said the valley typically sees 100-degree temperatures on at least two occasions in September.
"Last year, we never reached 100 at all," he said. "But we had a lot of 99s in September."
Today's high temperature should hit 97, Glaser said, and temperatures will hover in the low to mid 90s for at least a week.
"Summer will continue for a little longer," he said. "When it drops, it will go down in a hurry," he said.
Medford also reached 100 degrees on Sept. 7. August saw seven days of temperatures of 100 or greater. The hottest day of the summer was Aug. 4, when the mercury topped out at 107.
Glaser said nighttime temperatures give the impression that the area is actually cooler at this time of year.
Instead of a nighttime low of near 65 in August, the temperature is dropping into the 50s. The low for Thursday morning in Medford was 50 degrees, he said. Also, the hours of daylight are decreasing, so the heat dissipates quicker in the evening.
Glaser said there are no signs of rain in the forecast, just more hot weather.
"I don't see it ending for at least a week," he said.
Reach reporter Damian Mann at 541-776-4476, or email email@example.com.