The odds of a good chunk of the region hitting 90 tomorrow afternoon are pretty high. We're not going to say it's a lock but the odds are pretty high...I personally think a number of us will pull it off.
Historically, there have been 18 instances since 1874 where we've hit 95 degrees after September 10th -- the last of them being in 1983. More importantly, since the official reporting site was moved out of Center City in 1940 it's only happened eight times.
Some years -- like 1941 -- featured very hot temperatures even into early October as evidenced by our 96 and 95 degree record highs on October 5th and 6th, respectively. However, the odds of such late season heat occurring as we work past the 12th diminish markedly! Only nine of the 18 95 or hotter days after September 10th occurred after the 12th.
Our latest ever 90 degree day occurred on October 10th, 1939, which means that we theoretically have a month to go in the possible 90 degree season.
It's also a month to go until our earliest first snowfall (October 10th, 1979).