Climatologically speaking, September is one of the driest months of the year for Louisville averaging only about 3 inches of rainfall. Not so this time around. Despite a dry start to the month, it ended up being the second wettest on record for the city dating back to the 1870’s with a whopping 9.60 inches of rain!

After picking up only 0.03 inches of rainfall during the first nine days of the month, the rains began to fall on the 10th. In fact, strong thunderstorms dumped about 2 and 1/3 inches between the 10th and the 12th in Louisville as a slow moving cold front moved through the region. Following this first real rain event of the month, Kentuckiana saw a lull in activity over the next week and a half that would prove to be the calm before the storm.

On Friday September 22nd a powerful storm system began to move out of the plains and into the Ohio Valley bringing with it a surge of rainfall. Although steady rains moved into the area early during the day, it was Friday night that the heavens opened up on Kentuckiana. A strong complex of slow moving thunderstorms dumped an incredible amount of rain across the area creating a rash of flash flooding.

By the time the rain finally stopped on the 23rd, it was apparent that the Louisville area had been hit by its worst flooding since 1997. Unfortunately, six people lost their lives in the deluge across north-central Kentucky as six to nine inches of rain fell across much of the metro area mainly along the east to west I-64 corridor. Louisville set a rainfall record on the 22nd with 4.28 inches of rain, just 0.02 inches shy of the all-time September record.
Fortunately, unlike the 1997 flood, most small streams and rivers across the region were back in their banks within a few days after the storm.

An additional inch and a half of rain fell over the last four days of September. In total, Louisville saw rain on 13 of the 30 days of the month and the 9.60 inches recorded at the airport was second only to the 10.49 inches that fell in 1979. At this point, Louisville has picked up almost 46 and ½ inches of rain on the year which is about 12 inches above average. Considering the fact that Louisville only averages about 44 and ½ inches of rain per year, 2006 will end of wetter than average even if it doesn’t rain again for the rest of the year.

Not that we’re expecting to go another three months without rainfall, the near future, however, does look drier. Current weather models are pointing towards warmer and drier weather for the first half of October.