Officially, only about three-quarters of an inch of rain fell in Wilmington and Philadelphia in October. As puny as this sounds, the month didn't even qualify as one of the ten driest Octobers in Philadelphia, though it was the fifth driest in Wilmington. October is simply, on average, typically a dry month in this area.

Here's another way to look at it. We recently went through a stretch of more than two weeks without any rain. That length of dryness isn't unprecedented - we had a three-week stretch around this time last year. When you look at the months when long dry spells tend to occur in this area, about 80% of the time it's in September, October, or November - the three months considered meteorological autumn.

In fact, if we categorize precipitation by season, and then ask what were the driest seasons on record, the first five on the list are autumns.