From the NWS in Indianapolis:
Central Indiana October 2009 Climate Summary
October 2009 was a cold and very wet month. November like weather persisted for much of the first 18 days of October. From the 14th through the 16th temperatures did not reach 50 degrees in much of central Indiana. Maximum temperatures warmed by more than 20 degrees after the 19th. After beginning very cool, temperatures reached 70 degrees in many areas on the 21st, 23rd and 30th. The warm and rainy weather on the 30th stripped most of the remaining leaves from the trees.
Monthly temperatures during October 2009 averaged well below normal. Temperature departures ranged from 1 to nearly 5 degrees below normal. Compared to September, average temperatures declined 15 to 17 degrees. Typically temperatures fall around 12 degrees from September to October.
October began cold and remained cold through 18th. Temperatures did not rise out of the 40s in many areas from the 14th – 16th. Above normal temperatures generally prevailed after the 19th. Most areas reached the 70 degree mark several times from the 21st -30th. A few areas near the Ohio River in southeast Indiana touched 80 degrees on the 30th.
The growing season ended in all of central Indiana by the 18th. The coldest temperatures of the month occurred on the 18th when the temperature fell into the upper 20s to low 30s. No temperature records were set at Indianapolis this month.
At Indianapolis, there were 21 days with below normal temperatures, 9 days with above normal temperatures, and 1 day with exactly normal temperatures.
October 2009 tied for the 19th coldest in the Indianapolis area since 1871.
October 2009 was a very wet month for all of central Indiana. Rainfall exceeded 3 times the normal in areas of southern Indiana. Monthly rainfall ranged around 4½ inches to more than 10 inches in south central Indiana. Rain was so frequent that the Indiana agricultural community on October 20th set a new record low harvest pace for soybeans with only 34 percent harvested. The old record low for that date was 39 percent harvested in 1990. The longest dry period in October was only 5 or 6 days.
Unusual October river flooding occurred along the White River in southwest Indiana following rains of 2 to nearly 5 inches on the 8th and 9th. Lowland flooding lasted less than 2 days. Rain of 1 to 2 inches on the 30th pushed the Wabash, White and East Fork White Rivers in southern Indiana to near bank full levels.
October 2009 tied for the 9th wettest in the Indianapolis area since 1871.