June 2018
Monthly Overview - June 2018
Warm Again
On the heels of a record warm May, June was well above normal and ranked as the 13th warmest June since 1895. Though temperatures were near normal along the Great Lakes, inland areas were consistently above normal with monthly averages up to 5°F above normal in parts of Missouri
(Figure 1). The region as a whole averaged 2.7°F above normal and statewide averages ranged from 0.9°F above normal in Michigan to 4.4°F above normal in Missouri. Every Midwest state except Michigan ranked among the warmest 20% in their respective history, with Missouri ranking 8th warmest. Two-month averages for May and June ranked the region as the 2nd warmest with all nine states in their top 4 warmest. Daily record highs (986) swamped the record lows (90) in June. The vast majority of the records were record high minimum temperatures which were spread across all nine states and many days in June. Twelve days had at least 10 record highs recorded. Temperatures reached at least 98 in all nine states with a handful of stations reaching triple digits scattered across four states. Temperatures also dropped below 50°F in all nine states, below 40°F in four states, and to freezing or colder at a handful of stations in northern Minnesota and Upper Michigan.
Heavy Rains
Heavy rains were reported across the Midwest in June (Figure 2). Only Missouri (8.89") and Michigan (9.69") had their wettest station fail to top 10.00" for the month. Six states had stations with 12.00" or more and three had stations with 14.00" or more of precipitation. The region as a whole ranked as the 21st wettest in history with statewide totals among the wettest 10% in Indiana (150% of normal), Kentucky (143% of normal), and Iowa (152% of normal). Four more states ranked among the wettest 25% (with at least 123% of normal) with just Michigan (89% of normal) and Missouri (80% of normal) falling below normal
(Figure 3). Seven states had at least one station report a 5.00" or more daily rainfall total and the other two had stations that topped 3.00". More than 500 daily precipitation records were set or tied in June, with at least a couple dozen in every state and records on every day except the 5th. Calendar year-to-date (Jan-Jun) rankings put both Kentucky and Ohio as 9th wettest, while water year-to-date (Oct-Jun) ranked among the wettest in Michigan (3rd), Ohio (4th), and Indiana (7th).
Severe Weather
Severe weather was reported on every day of June somewhere in the region (well over 1000 reports). High winds were reported every day of June with large hail reported on 23 days and tornadoes on 14 days. All nine Midwest states had high winds and large hail reported and only Michigan was without a tornado report during the month. The busiest days for severe weather were the 9th (Figure 4), 26th
(Figure 5), and the 28th (Figure 6). Multiple tornadoes were reported in four states (Illinois, Kentucky, Missouri, and Wisconsin) on the 26th alone. On the 9th in Kentucky, tow people were injured when a tree was blown down onto their mobile home. Late in the month, two others were injured in separate incidents in Missouri when they were struck by and awning and a tree that were blown down by thunderstorm winds.
Flooding and Flash Flooding
Flooding and flash flooding was a problem numerous times during the month due to the heavy rains. Flash flooding in Illinois and Indiana on the 9th to the 12th was due to thunderstorms that tracked over the same areas for extended periods. Flash flooding in Upper Michigan and northeastern Wisconsin on the 16th to the 19th washed away roads and caused one flooding death. Many locations in these areas had rainfall totals above 6", with some isolated totals up to 12". The 20th and 21st saw flooding in northwestern Iowa. Area rivers quickly rose to major flood levels, with one location on the Little Sioux River (Linn Grove, Iowa) setting a new record flood level. The Mississippi River rose to moderate flood levels form southeastern Iowa to northeastern Missouri during the last week or so of June.
Drought Hangs On Near Iowa-Missouri Border
Drought in the Midwest was largely limited tot he Iowa-Missouri border at the beginning of June
(Figure 7), representing just under 4% of the region (with less than 0.25% in severe drought). By the end of the month, the area in drought expanded to include much of northern Missouri and covered more than 6% of the region (with nearly 3% in severe drought). Despite the expansion and intensification of the drought in this area, the area of the Midwest classified as abnormally dry shrunk from more than 20% of the region to just over 11% of the region in the same time frame.
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