September continues a relatively normal look overall. The average temperature so far has been 71.0 degrees, just 0.6 degrees above average through yesterday. This is the most "normal" month we've had since June, only the second month in the last 13 where the temperature departure has been less than one degree above average and, in fact, we haven't been below average since August 2011 in Philadelphia.
In terms of daily breakdown, September and June have been the months with the most below average days as a percentage of total days in the month. September has featured 11 days so far (not including anything that happens today) of below average temperatures and just 12 days above average. All 11 of those below average days have come in the last 16 days...we've only had four above average and one average day since September 9th as Fall has eased into the region. Despite the run of coolness, the average temperature departure over the last 16 days has been just -1.2 degrees from average. It's been cool but nothing atypical as we have had occasional warm days thrown in.
June, with half of the days below average, was the only other month with a higher percentage of below normal days so far.
Despite the cool streak as of late, the year has been rather warm overall. 70% of our days have been above average, thanks to insanely high percentages of above average days in February and July.