According to Gothamist, this year's span of June through September was the warmest four consecutive months ever measured in Central Park. And this, as we enter October still wearing short sleeves, and seeing forecasts of highs in the 70s at least until Thursday.
In semi-related news -- unseasonably warm weather or no -- fall foliage time is just around the corner. The Weather Channel is always a great source for the current and typical peak-color maps for the Northeast. According to the "normal" map, NYC is scheduled to hit its peak in late October, as with all the other major cities nearby: Boston, Philly, D.C.