What Is the Greatest Rainfall in a 24-Hour Period?

The tiny island of Réunion holds the record for the greatest rainfall in a 24-hour period, as well as several other rainfall records. From 15 to 16 March 1952, the municipality of Cialos had rainfall of 74 inches (1,850 mm) in a single 24-hour period. The island also holds records for the most rainfall in 12-, 48-, 72- and 96-hour periods.

More facts about rainfall records:

• Mawsynram, India, is considered the wettest place on the planet. The area receives an average of 474.8 inches (11,870 mm) of rain per year.


• Mount Wai-'ale-'ale in Hawaii experiences the highest average number of rainy days annually. At a height of 5,148 feet (1,569 mm), the area receives rain for more than 350 days per year.


• Many people think that the wettest city in the continental United States is Seattle, Washington, but it's actually Mobile, Alabama. The city experiences an average of 67 inches (1701.8 mm) per year, with an average of 59 rainy days annually. In fact, most of the top 10 wettest cities in the nation are located in the South. Seattle does not make the Top 10.