CHICAGO (CBS) – Saturday was the warmest mid-October day in Chicago in more than 35 years.

The high temperature in Chicago Saturday reached 86 degrees, tying the record for the warmest temperature ever recorded on Oct. 9, according to the National Weather Service’s Web site.

The last time the temperature got this warm this late in the year in Chicago was in 1975, when the high reached 89 degrees Oct. 14, the weather service said.

Saturday was only the 20th time in the 121-year recorded history of Chicago weather that a temperature that warm was reached this late in the year, the weather service said. That is about a 1-in-150 chance of setting a record high on any given day this late in October.

Temperatures reached the high 70s Sunday, and are expected to be in the 60s and 70s the remainder of the week.

The unseasonable heat over the weekend came just in time for the Chicago Marathon Sunday. Race officials said 65 runners were hospitalized — a number in line with past years. There were no fatalities.

The heat for the Marathon has been far worse in past years. Back in 2007, the temperature reached 88 degrees on Marathon Sunday, which that year was Oct. 7. The Marathon was ultimately called off early, as hundreds of runners began collapsing from the heat. One runner, Chad Schieber of Midland Mich., died that year, but an autopsy showed it was a heart condition that caused his death, rather than the heat.

The Sun-Times media Wire contributed to this report.