Tornadoes - July 2018
This analysis is based on preliminary data available from the Storm Prediction Center. Final tornado counts published by the Storm Prediction Center and NCEI's Storm Events Database might differ from this report. For a more detailed climatology, please visit our tornado climatology page.
According to data from NOAA's Storm Prediction Center, during July, there were 96 preliminary tornado reports. This is below the 1991-2010 average of 134 for the month. Few tornadoes impacted the nation during the first two and a half weeks of the month with activity picking up towards the end of July. The biggest outbreak occurred on July 19th and 20th when 40 tornadoes were reported across the Midwest. For the year-to-date, there have been 692 preliminary tornado reports, below the average of 952. Depending on the final confirmation rate, the January-June tornado count could be the lowest since 2002 when there were just 536 tornadoes.
On July 19-20, a strong storm system moved through the Midwest causing tornadoes, strong winds, and hail across the region and one of the largest severe weather outbreaks of the year-to-date. On the 19th, there were 31 preliminary tornado reports across southern Minnesota, central Wisconsin and central Iowa. Central Iowa was the hardest hit with at least 13 tornadoes confirmed. The most damaging tornado of the event hit Marshalltown, Iowa. The EF-3 tornado had estimated winds of 144 mph and a width of 900 yards and tacked 8.26 miles. The tornado moved through the central business district of the town and nearby residential areas causing significant damage to the town including to the County Courthouse. On the 20th the storm system continued to move eastward and spawned nine tornado reports across Wisconsin, Indiana and Kentucky. These tornadoes were weaker than the day before, but still resulted in minor damage. Outside of the tornado reports, severe winds and large hail were widespread across the region. According to preliminary information, there were no tornado-related fatalities reported during the outbreak.