Record rainfall in every state
There are several types of rainy days, ranging from wet afternoons to soggy days to torrential downpours. Then come the absolute rainiest days in history, where record levels of precipitation fall in 24 hours. Stacker turned to the State Climate Extremes Committee (SCEC) of the National Oceanographic and Atmospheric Administration (NOAA), to track these days in each state except for Kansas, as it had no data available.
Along with the number of inches in 24 hours, some NOAA data detailed the devastating damage and lives lost during some of the rainiest days. While some of the specific rain days were caused by hurricanes and tropical storms, others were simply soaking wet days. Climate change-related rainfall has become a concern, with many experts predicting dangerous water cycles, rising sea levels, and other irregular weather patterns to come.
In describing precipitation measurement missions and climate change, the National Aeronautics and Space Administration (NASA) detailed that since 1900, the average U.S. precipitation has risen overall. At the same time, severe droughts and floods have become an increasing problem, with their incidence varying across the country.
“Projections of future climate over the U.S. suggest that the recent trend towards increased heavy precipitation events will continue,” reports NASA. “This trend is projected to occur even in regions where total precipitation is expected to decrease, such as the Southwest.” The year 2018 made records for rainfall across eastern and southern U.S., and during Hurricane Florence, nearly one quarter of Wilmington, N.C.'s 102.40-inch rainfall took place in just four days. As meteorologists continue to look to the past to determine possible future weather patterns, the following dates will remain notable until the next wettest day.
Read on to find out the biggest rain day ever recorded in every state.
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- All-time highest 24-hour precipitation: 5.08 inches
- Location: Deer Creek Dam
- Date: Feb.1, 1963
Unusual variations in the temperature soundings from this Feb. 1, 1964 storm merited investigation, according to the U.S. weather bureau in Salt Lake City. No thunder, but two streaks of lightning occurred as sheets of heavy rain fell in the early morning hours, according to personal accounts of the storm over Deer Creek Dam.
- All-time highest 24-hour precipitation: 6.06 inches
- Location: Cheyenne
- Date: Aug. 1, 1985
Fast-rising waters and flash floods swept through Wyoming in 1985 unlike ever before. In just three hours, 6.06 inches of rain and 2-inch hailstones fell hard over Cheyenne, killing 12 and causing $61 million in damage. “When it started raining, it just kept going," Cheyenne Police Chief Byron Rookstool said in a 2010 Star Tribune report. Safety measures taken since to prevent severe overflow include diverting flood channels, implementing city-regulated flood plains, and creating large retention ponds around neighborhoods.
- All-time highest 24-hour precipitation: 7.17 inches
- Location: Rattlesnake Creek
- Date: Nov. 23, 1909
The northern region of Idaho received the state's most rain in 24 hours at the end of 1909. Ironically, the 7.17 inches of rainwater that fell at Rattlesnake Creek was nowhere to be found the following year in the Great Fire of Idaho, which destroyed 3 million timber acres and killed 87 people in two days. The highest annual precipitation in the Gem State was 81.05 inches in 1933, also in Idaho's northern region of Roland.
- All-time highest 24-hour precipitation: 7.78 inches
- Location: Mount Charleston
- Date: Oct. 20, 2004
In October 2004, more rain fell over Mount Charleston—which is almost 12,000 feet high—than in any other area of Nevada. Located in the Spring Mountains section of the Humboldt-Toiyabe National Forest, Mt. Charleston only sees an average of 8 inches annually, making the 2004 rain date of almost 8 inches unusually high. As the 8th most prominent U.S. peak engraved with hiking and ski trails, Mount Charleston is also famous for the crash of the 1955 CIA C-54 plane headed to Area 51.
#45. North Dakota
- All-time highest 24-hour precipitation: 8.1 inches
- Location: Litchville
- Date: June 29, 1975
Litchville, N.D., sees anywhere from 13 to 21 inches of precipitation every 12 months, but in 1975 it rained almost 8.1 inches in 24 hours. Nearly a half-century later, June remains the wettest month with at 3–4 inches of rain on average, according to the North Dakota Game and Fish Department. Located in the center of the U.S., North Dakota experiences a continental climate, consisting of very cold winters and extremely hot summers.
- All-time highest 24-hour precipitation: 8.5 inches
- Location: Dover
- Date: July 13, 1975
With an average of 41 inches annually, Delaware's 1975 day of 8.5 inches makes rain record history for the Diamond State. That day is among many other notable rainy days, according to Delaware Online, which reported four Delaware counties saw 60–80 inches in rain 1948; two counties saw 60–80 inches in 1996; and two counties saw 57–62 inches in 2003. By 2019, some parts of Delaware had the most rain recorded in nearly a century, according to climatologist Daniel Leathers, who said Delaware “should be in the top, maybe top three years, for precipitation across the state as a whole."
#43. South Dakota
- All-time highest 24-hour precipitation: 8.74 inches
- Location: Groton
- Date: May 6, 2007
Flooded basements and cellar wall collapse were the devastating results of South Dakota's most drenched day in history. President George W. Bush declared Brown, Buffalo, Clark, Day, Marshall, and Spink counties disaster areas, while widespread power outages, stalled roadside vehicles, and backed up drainage systems statewide caused a state of emergency. Hundreds of South Dakota homes and crops got condemned due to the 24-hour rain event.
- All-time highest 24-hour precipitation: 9.78 inches
- Location: Bloomingdale
- Date: Aug. 31, 1914
On an August day during the first year of World War I, 9.78 inches of rain fell in Michigan's Bloomingdale, compared to the approximate 33 inches of rain the state sees annually. In August 2017, the Detroit Free Press cited the 105-year-old storm when predicting how Hurricane Harvey, which devastated Texas, might hurt Michigan.
- All-time highest 24-hour precipitation: 9.92 inches
- Location: Mount Mansfield
- Date: Sept. 17, 1999
At the end of the 20th Century, Vermont's highest summit Mount Mansfield also became the location of the state's most rainfall in 24 hours. Aside from almost 10 inches of rain falling that afternoon 20 years ago, discussions of abortion were taking place in Missouri and musician Oscar Peterson debuted at Carnegie Hall the same Friday, NPR reported.
- All-time highest 24-hour precipitation: 10.48 inches
- Location: Louisville
- Date: March 1, 1997
Copious amounts of rain kept the middle of the Ohio River beyond the flood stage until March 16, 1997, but the first two days of the month were the rainiest. The storm killed 20 people, nine of whom attempted to cross flooded streets. After the heaviest day of rain March 1, the Ohio River reached its highest peak since 1964. The damage to Louisville homes and businesses totaled $200 million, and the surrounding area also suffered an additional $200 million in destruction.2018 All rights reserved.