Although the past two days were quite mild, as a whole, the first 15 days of October finished about 5 degrees below normal. That is an incredible 19 degrees colder than the first half of October last year. Although, it should be noted, that the first half of October 2011 was the warmest such period on record. The second half of 2011 and much of this year recorded above average temperatures.
Then the past two months, August and September, finished near normal and the current pattern, at least for now, has transitioned to a cold one. The last time with an extended period of below average temperatures was in May, 2011. Looking forward, it appears much of the rest of the month will record temperatures below normal, meaning that this month will likely be the coldest, based on the average, in 17 months.
This October has not only been cool, but also dry, with only 0.43 inches recorded through Monday which is 0.67 inches below average.