Millersville's Director Of Meteorology look at October:
For anybody starting to think that fall may be here to stay, don't be fooled! This is only a temporary change in the weather pattern, and there are no signs that a prolonged stretch of cooler weather is anywhere in sight. Strong and persistent, westerly flow from the Pacific should flood much of Canada and the northern U.S. with unseasonably mild air through at least the first half of October. In addition, a deep trough oscillating between Alaska and the West Coast of the U.S. means the only way we'll get any "chilly" weather here in LanCo. is if a storm system temporarily cuts off over us, leading to persistent clouds and showers. Thus, I foresee a relatively mild October (1-3 degrees above normal) ahead with the number of abnormally warm days outnumbering the number of cool days.
On cue with this thinking, unseasonably warm air will rush back into Pennsylvania this weekend as warm, southwesterly flow returns. Highs will easily reach the middle 70s on Saturday, and it's not out of the question we crack or exceed the 80-degree mark on Sunday and/or Monday. Our next chance for rain won't arrive until a cold front pushes slowly eastward through the state later on Monday or Tuesday (Oct. 3-4), and chances are that temperatures behind this front won't fall much below normal (if at all!).