...1809... Three tornadoes crossed through the town of Cincinnati, Ohio and then traveled up the Ohio valley.
...1880... Savoy, Texas was hit by an F4 tornado. 14 people were killed and 60 were injured. It leveled the entire business and northeast residential sections. The tornado was described as "a funnel blazing with balls of fire".
...1887... The temperature reached 97 degrees at San Francisco, California, establishing a record high temperature for the month of May for the city.
...1917... 2.48 inches of rain fell at Newport, Rhode Island, breaking the record of 2.33 inches set in 1906.
...1931... At Newport, Rhode Island the high temperature peaked at 88 degrees, setting the record high for the date. It was later tied in 1931, 1959 and 1991.
...1942... The latest snowstorm of record for the state of Iowa left ten inches at LeMars, eight inches at Cherokee, and 7.5 inches at Waukon. Afternoon highs were in the lower 30s in parts of northwestern Iowa.
...1947... A storm produced heavy snow across Wisconsin, with ten inches reported at Gay Mills. The snow damaged fruit and other trees, and downed power lines. The storm was followed by the coldest weather of the month for much of the High Plains Region and Missouri Valley. Williston ND reported a low of 21 degrees the morning of the 28th, and the next morning Cheyenne WY reported a morning low of 16 above zero.
...1984... Sacramento, California had their hottest temperature ever recorded in the month of May, when the temperature reached 110 degrees. This broke the old record of 100 degrees which was set in 1932.
...1987... Thunderstorms produced torrential rains in Oklahoma and northern Texas. Lake Altus OK was deluged with nine inches of rain. Up to eight inches drenched northern Texas, and baseball size hail was reported north of Seminole and at Knickerbocker. Ten to 13 inch rains soaked central Oklahoma the last five days of May resulting in an estimated 65 million dollars damage, and forcing several thousand persons to evacuate their homes, many by boat or helicopter.
...1988... A sharp cold front began to usher cold, wet and windy weather into the western U.S. Thunderstorms in the Great Plains Region produced wind gusts to 80 mph near Brookings SD.
...1989... Unseasonably hot weather continued in Florida. Five cities reported record high temperatures for the date. The record high of 98 degrees at Lakeland FL was their fifth in a row. Thunderstorms produced severe weather in Florida late in the day, with golf ball size hail reported at Kissimmee.
...1990... Two to five inches of rain over southeastern Ohio on the 28th and 29th capped an exceptionally wet month of May, and triggered widespread flooding. Flooding which resulted claimed three lives, and caused millions of dollars damage. Numerous roads in southeast Ohio were flooded and impassable, and many other roads were blocked by landslides.
...1991... The heat index was a hot 92 degrees on this day at Newport, Rhode Island, breaking the record of 89 degrees that was set in 1959.
...1994... At Newport, Rhode Island the low temperature dipped to 41 degrees, breaking the record of 42 degrees that was set in 1922, 1967 and 1972. The wind chill got down to 38 degrees, setting the record low for the date.
An F4 tornado moved through Jefferson, Bullitt, and Spencer Counties in Kentucky, injuring 10 people and doing $100 million in damages.