This September was the warmest on record in Bend, thanks to the absence of rainstorms and a 12-day string of high temperatures at or above 84 degrees.

“Most of the days were sunny,” said Dennis Hull, a meteorologist with the National Weather Service in Pendleton.

The average temperature for the month was 62.5 degrees, about 6 degrees above normal and the highest such average in the 110 years the agency has been keeping records in Bend. The weather service started record-keeping in Bend in January 1901, and the previous warmest September was in 1938, when the average temperature was 61.6 degrees.

A high pressure system over Central Oregon boosted temperatures from Sept. 4 to Sept. 15, said Marilyn Lohmann, a forecaster at the weather service’s Pendleton office, which forecasts for Bend.

“So those were 10 to 15 degrees above normal,” she said.

The high temperature for the month was 90 and hit on five days — Sept. 4, 6, 10, 11 and 25 — according to weather service data. The lowest temperature was 34 and recorded on four days — Sept. 1, 2, 29 and 30.

A half an inch of rain typically falls on Bend in September, according to the weather service, but this year there was only one day, Sept. 15, with a trace of rain.

Redmond also had a warm, dry September, according to data collected at Roberts Field.

Redmond had its fourth-warmest September on record, Hull said. The warmest happened in 1998, when temperatures averaged 64.8 degrees. The city experienced only a trace of rain on Sept. 5 and 14.

The hot September followed a warmer than normal August, but June and July were a couple of degrees cooler than normal.

“So it took a long time to get the summer going, and it was kind of short,” Lohmann said.

Less than a week into October, the weather has turned colder and wetter. Light rains spattered Bend on Monday, and more rain was expected Monday night.

There then should be a reprieve today, said Mary Wister, meteorologist with the weather service in Pendleton.

“It looks like it will return (this) evening,” she said.

Along with the rain, the early October storm systems are bringing lower temperatures. Today’s high should be 61. Wednesday and Thursday should have highs in the mid 50s before a return to sun and a high in the 60s Friday.