Midwest Overview - June 2012

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Dry Except for the Upper Midwest

June was a relatively dry month for most of the Midwest but above normal precipitation fell in the upper Midwest states of Minnesota, Wisconsin, and Michigan with the heaviest rains falling just to the west of Lake Superior (Figure 1). Daily precipitation records were led by records in the Duluth, Minnesota (St. Louis County) area from rains that fell on the 19th and the 20th (Figure 2). Rainfall totals for the two days exceeded the usual monthly amounts for many locations with one location in northeast Duluth reporting over 10". Severe flash flooding buckled pavement, washed out roads, and created sinkholes. Though no injuries were reported, the extensive damage is expected to take months to repair. In Clark County, Wisconsin a washout in the early morning hours on the 21st swept away 50 feet of Highway M and three people died when two cars crashed into the 12 foot deep trench.

Most of the area to the south had less than 75% of normal precipitation with large areas of less than 50%. Pockets of 10% to 25% of normal precipitations were scattered across several states (Figure 3). Drought areas expanded across the southern two-thirds of the Midwest due to the lack of rain. The dry weather for the second straight month in this area led to rapid intensification of drought conditions (Figure 4). Area in drought quadrupled during June and areas in Severe Drought increased from less than 2% to more than 15% while Extreme Drought was introduced to over 5% of the Midwest during the month. Pastures were in much worse shape than normal for this time of year and row crops were showing signs of severe stress in the driest areas. On some of the hardest hit fields, row crops failed to emerge or were a total loss as plants failed to mature.
 

Temperatures Slightly Above Normal

Temperatures fluctuated throughout the month, averaging near normal in the southeast and a few degrees above normal in the rest of the Midwest (Figure 5). Very warm conditions in the High Plains states moved into the Midwest during the last few days of the month bringing temperatures exceeding 100°F to most of the southern Midwest (Figure 6). For many locations, these temperatures were the warmest readings in several decades. The 108°F tempearture on June 29th in Paducah, Kentucky was the warmest since 1942. June 28th hit 108°F in St. Louis and 104°F in Indianapolis for the warmest temperature in those cities since 1954. Daily temperature records swung back and forth from record lows to record highs during June leading up to a few dozen all-time record highs on the last three days of the month.
 

Record Low Heating Degree Day Totals for the Year

Heating degree days (HDD) accumulate over a year defined as July to June. The 2011-2012 year will set new records in several states for the fewest HDD in a year. Preliminary numbers indicate that all nine Midwest states will rank among the bottom three of HDD accumulations for a year going back to the year 1895-1896. Several states are expected to set a new record for fewest HDD in a year including Minnesota, Wisconsin, Iowa, Missouri, and Illinois when the final numbers are tabulated.

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The Indiana State Climate Office also contributed to this report.
The Minnesota State Climatology Office also contributed to this report.