Read probability with its definition
A precipitation probability is tied to a forecast period and geographic area. Providers may define and display it differently, so use the legend or help text for that forecast. It is not a guarantee that rain will occur at a particular point.
Use a time window
Look for the forecast's start and end times, time zone, and update date. A broad time window can hide short changes, while a detailed map can still be uncertain farther into the future.
Combine sources carefully
Radar and station observations describe recent or current conditions; forecasts estimate what may happen later. They can differ because they measure different things and cover different times.