Monday's high of 76° is likely the last day we'll see highs in the 70s this year. If today's date were to be the last 70° day, it would fall just shy of the average date ( Oct 30th) but later than the last three years. 

With 40s and 50s forecast well into next week, it's not looking promising for a resurgence of 70s this year. The latest 70° on record is December 4th, that happened in 2001.  

Update: Midnight Tuesday, the temperature was still 72° in South Bend, making the 28th the latest 70° day of 2014.