We missed a tie with the largest 2 day temperature change by just 2 degrees. That occurred in 2008 when the temperature dropped 76 degrees between December 14 and 15. But what happened this week is certainly a record for the largest temperature swing in October. No other October dates even appear on the list of the top 25 largest changes over 1 or 2 days.
In addition, the record low of 13 degrees on Wednesday and 9 degrees on Thursday shattered the old records by 4 degrees and 13 degrees respectively. This is remarkable since most records are usually broken by just a degree or two regardless if it's a record high or a record low.