Excessive Heat in Plymouth, Iowa

Dangerous heat index values peaked as high as 110 degrees 5 miles north of Sioux City, 107 degrees near Westfield, and 106 degrees 5 miles west of Brunsville.

High levels of moisture pooled along and ahead of an outflow boundary across eastern South Dakota and southwest Minnesota with dew point readings into the the upper 70s to lower 80s. With temperatures in the upper 80s to lower 90s, heat index values generally reached the 100 to 110 degree range during the mid afternoon to early evening.