It is normal for our weather to fluctuate from colder than average to warmer than average. This natural and typical variation is not reflected in the daily averages of high and low temperature. The general trend from September through December is always a cooling trend, but not necessarily a smooth one.
This year, for example, the last two weeks of October produced an average daily mean temperature a full ten degrees colder than the first two weeks of November. Such temporary aberrations are not unusual, but we would never expect the entire month of November to be warmer than the entire month of October. The reduction in solar radiation simply will not allow for that. Likewise, once winter arrives, it is possible for the coldest day or week of the winter to happen any time through mid-March even though the coldest part of winter, on average, is in January.