Data

Whether or not it rains a week from now where you live may seem mostly random, but a long enough data record will likely reveal rainfall patterns that repeat over hours, months, or years. Atmospheric scientists describe some of these repeating patterns as cycles and others as oscillations. There are annual and daily precipitation cycles tied to the variation of the sun's path across the sky [1]. An example of precipitation affected by time of day is that summer thunderstorms occur predominantly in afternoon or early evening along the East Coast of the United States. An example of seasonal

In many places, the amount of that rain falls on a particular day or hour is influenced by multiple natural cycles that exist simultaneously on different time scales. One such cycle repeats every 24 hours, and another repeats every year. The global extent of these cycles can be studied using NASA's IMERG precipitation estimates that have been generated for 1998 to the present. Most of Earth's precipitation falls as rain, and the rest falls as snow, hail, or other forms of precipitation. The length of IMERG's data record makes it possible to average out some of the random error and unrelated

RAIN Global Viewer Regional Animations of IMERG in Near-realtime - Global Edition Visualize and animated near-realtime NASA IMERG satellite precipitation estimates. NOTE: This app is intended to be viewed on a large computer monitor. Click Here to view Fullscreen

NASA's Worldview website now allows you to explore global estimates of rainfall and snowfall from 1998 to the present at 30-minute intervals. Researchers and application developers have been using this dataset since 2014 (Portier 2024; Portier et al. 2023), but now it is also available as images in Worldview.