Below Average Temperatures Continue

Temperatures throughout the Midwest were well below average again this week, with the largest deviations (up to -12°F) occurring throughout Iowa, Missouri, Illinois, and Minnesota (Figure 1). Average maximum temperatures were also much cooler than normal this week. Far northern portions of Minnesota and Wisconsin, as well as northern and eastern Michigan, saw maximum temperatures up to 14°F below normal (Figure 2). Average minimum temperatures were also significantly below normal. Much of the region was more than 6°F below normal, with parts of Iowa and Missouri as much as 16°F below normal (Figure 3). There were 292 low minimum and 197 low maximum temperature records broken or tied this week (Figure 4).

Dry Conditions

The southern and western portion of the Midwest was extraordinarily dry this week. Much of Iowa and Missouri, as well as parts of Minnesota, Wisconsin, Illinois, Indiana, and Kentucky, received less than 5 percent of normal precipitation (Figure 5). However, much of Michigan saw up to 200 percent of normal precipitation, with some areas receiving 400 percent of normal. The highest precipitation (4.84 inches) was recoreded in Alger County, Michigan. A majority of stations in the southern and western Midwest had the driest third week of October on record while Michigan had stations in the top 10 wettest third week of October on record. Traverse City, MI set a record for the wettest Week 3 of October on record (Figure 7). Below normal streamflows continued throughout the Midwest this week (Figure 9).

Snowfall

More locations in the Midwest saw the first snowfall of the season, including Chicago. Snowfall totals in excess of 10 inches were measured in the Upper Peninsula of Michigan (Figure 8). Tri-Lakes, located in Northeastern Indiana, also received 3.3 inches of lake effect snow.

Drought Monitor Update

Abnormal dryness and drought affected 78.26% of the Midwest this week according to the October 18 US Drought Monitor (Figure 10), with conditions generally unchanged in the past week.