National Weather Service United States Department of Commerce

Lala Impacting Hawaii; Flash Flooding Risks; Excessive Heat

Lala will continue to impact Hawaii through the weekend. Heavy rainfall, strong winds, dangerous surf and localized flooding are expected. Thunderstorms, heavy rainfall and flash flooding concerns from the mid-Mississippi Valley, Ohio Valley into the central Appalachians and the mid-Atlantic through today. Record heat continues for areas of the Mississippi Valley into the Southeast. Read More >

Flood Return Period Calculator

Though this calculator is worded for the flood event return period it would work for any extreme weather event.

 

Enter the return period (ie..100 year flood)

Percent chance of occurrence

year flood %
Enter the number of years (ie..over the next 10 years)
There is a % chance that a year flood will occur over the next year(s)
year(s)