Warm Weather Continues
Another week of above-normal temperatures were common across the Midwest
(Figure 1). The warmest areas were in the Ohio Valley, where temperatures were 6-9°F above normal. Most of Missouri, Illinois and Lower Michigan were 4-6°F above normal, while Iowa was 2-4°F above normal. Only northern Minnesota and a small portion of Michigan's Upper Penninsula were near to slightly below normal. Most of this warmth occurred during the beginning of the week, where dozens of daily high maximum and high minimum temperature records were broken on October 18-20. Most of these records occurred in the southern third of the region.
A Few Wet Days
Two storms accounted for most of the precipitation during the period (Figure 2). These storms dropped above-normal precipitation on parts of the Ohio River Valley, Missouri, northern Wisconsin and the U.P. of Michigan
(Figure 3). Through the morning of October 18, more than two inches of rain fell across portions of Wisconsin and northern Michigan (Figure 4). Locally heavier amounts over three inches were recorded. Several reports of over three inches were found near Florence, WI (Florence County) with reports of over 3.50 inches in Rhinelander, WI (Oneida County). A stationary boundary caused heavy rain across southern portions of Missouri, Illinois, and Indiana and Ohio through the mornings of October 20 and October 21
(Figure 5) (Figure 6). Two inches of rain were common across southern Missouri, Ohio and Illinois, with amounts over four inches in southern Indiana. In most cases, this was more than double the normal amount
(Figure 7). Some of the heavier two-day totals included 4.67 inches near Vernon, IN (Jennings County) and 4.59 inches at the Shakamak State Park, IN (Sullivan County).
Later Than Usual First Fall Freeze
Warm temperatures across the Midwest during September and October have led to later than usual first fall freezes across much of the Midwest (Figure 8). The first freeze of the fall occurred in southern Lower Michigan and Iowa during the week, which was around a week later than average
(Figure 9). Most of Missouri, Illinois, Indiana and Ohio have yet to have a freeze this fall. These areas have average freeze dates during mid-October.