Midwest Overview - July 2009
This was the coldest July on record for the nine-state Midwest region, based on preliminary temperature data. The average temperature for the region was 68.0°F, 4.7°F below normal. The previous record was 68.9°F in 1992. Illinois, Indiana, and Iowa also set their state record in July. Wisconsin, Michigan, Ohio, and Kentucky recorded their second coldest July, while Minnesota was third and Missouri was fourth.
The entire Midwest was below normal ranging from about 2°F below normal in eastern Ohio to as much as 6°F below normal in eastern Iowa (Figure 1). The region was below normal nearly every day in July with two particularly cold periods, July 1-9 and July 17-23. There were fewer than 20 record highs observed while more than 1800 record lows were recorded in July. The record lows were spread across all nine states (Figure 2) with the number of record lows in each state ranging from just over a hundred in Ohio to more than 250 in Wisconsin, Iowa, Illinois, and Missouri.
High temperatures were depressed more so than minimum temperatures. Of the 1832 record lows, 444 were record low minimum temperatures and 1388 were record low maximum temperatures. 90°F days were much rarer than normal for July (Figure 3). Typical counts range up to the middle teens in the southern Midwest, but July 2009 had about a dozen fewer 90°F days than normal.
Many stations in the Midwest recorded their coolest July in 2009.
Precipitation varied from below 50% of normal in central Minnesota and most of Wisconsin to as much as 150% of normal in southern Missouri, southern Illinois, western Kentucky, and along the Ohio River (Figure 4). Two additional areas of above normal precipitation were northwest Iowa and along the Mississippi River in eastern Iowa and northwest Illinois. Drought conditions persist across east central Minnesota, the northern two-thirds of Wisconsin, and upper Michigan. An emerging dry area extends from central Ohio into northern Indiana and southern Michigan.
Crops Behind Schedule
Crops across the Midwest are developing behind schedule but the reasons vary. Delayed development can be attributed to late planting, dry conditions, and the cool weather in various parts of the region. Some warmer weather would be welcome to accelerate growth but additional water would be needed from Minnesota to Ohio in order to avoid stressing the crops.
Severe weather has been somewhat dampened by the cool weather in July. On nine days there were a total of 27 tornado reports in the Midwest during July. Lightning caused the only Midwest weather fatality in July when a teenager was struck in Minnesota on July 21st.
River flooding has been largely absent in July. This spring’s high water has receded and Midwest rivers have largely remained in their banks throughout the month.
For more details on weather and climate events during July 2009, click on the individual weekly report links on the upper right.