August Anomalies ...

Pat Guinan
State Climatologist
Commercial Agriculture/University of Missouri Extension

August is a period that we like to refer to as the summer doldrums or dog days of summer, where the monotony of hot and humid weather conditions have all of us yearning for a change in the weather. Every once in a while, however, Mother Nature likes to throw a curve ball, and surprise us with some unusual or extreme weather, even during what we consider our most mundane time of year.

August is typically a month when Missouri experiences the fewest tornadoes with only 39 documented tornadoes reported since 1950. With the exception of one, all August tornadoes have been classified as weak, causing little property damage and no casualties. The notable exception was a tornado that occurred in Sedalia during the early morning hours of August 20, 1952. It was the 50th anniversary of the Missouri State Fair, when a strong tornado roared through the fairgrounds at 1:20 a.m. The tornado's path was one mile long and 300 yards wide, centered on the midway area, where one carnival employee was killed. Additionally, 13 people were injured in the fairgrounds as it caused extensive damage to numerous buildings. Damage estimates, at the time, were over 1 million dollars.

Rainfall during August usually arrives in the form of scattered thunderstorm activity during the heat of the afternoon. Average August precipitation over Missouri ranges from 3.5 to 4 inches, but there have been years when much more, or less, rain has fallen during the month. The wettest August occurred in 1915 when an average of 8.21 inches fell across the state. With regard to the most rain ever recorded during August, that dubious distinction goes to a rural northeastern community located in Scotland county. In August of 1970, Memphis, MO received 21.96 inches of rain with over a foot falling during the first 8 days of the month!

Alternatively, in 1909, the average statewide rainfall was a paltry 0.60" for the month making it the driest August on record for Missouri. There have been a few locations in the state that have recorded no rain during the month of August, especially during the years 1909, 1913, 1936, 1953, 1984 and 2000.

Even though the dog days of summer have a tendency to be uneventful, it's apparent that is not always the case.