Prior to last Thursday, we hadn't seen any rain - not a drop - for three weeks. That 21-day stretch goes into the books as the fourth longest dry spell in the official records, which in Philadelphia go all the way back to 1872.

We didn't come close to the all-time record, which is 29 days. That was set back in October and November of 1874, beating out the next-longest dry spell by a whole week. What's interesting about these long dry spells is that almost all of them occur this time of year.

In an earlier Franklin Fact, I discussed how autumn tends to be the most tranquil season weatherwise - on average, our driest season. In 128 years of records, there've only been six times when we've had a stretch of 20 or more days without a drop of rain. All of those stretches either started or ended in September or October, and four of the six fell between October 10 and Thanksgiving.