U.S. winter (December–February) precipitation for every El Niño since 1950. Maps are ordered from upper left to bottom right based on the strength of the event during winter, based on the Relative Oceanic Niño Index value. Places that were wetter than average are blue-green; places that were drier than average are brown. Details and other formats. Climate.us maps, based on NOAA nclimgrid data.