Start with the time and the legend
Find the time of the displayed radar frame before interpreting it. If animation is playing, you may be viewing an earlier frame. Read that map’s legend: colors are chosen for the product, so a color on one map may mean something different on another.
What reflectivity means
Reflectivity measures energy returned to the radar by targets such as raindrops, snow and hail. It is commonly labeled dBZ. Stronger returns often suggest heavier precipitation, but hail and the size of raindrops can change the return. A color alone is not a precise rainfall amount.
Use animation as recent history
Compare several timestamps to see how precipitation has moved and changed. The loop shows observations already collected. It does not guarantee where a storm will go next or exactly when rain will reach your address.
Do not use a quiet map as permission to stay outside
Radar samples the atmosphere rather than measuring conditions at every home. Products and scan heights differ. Missing coverage or unavailable frames leave gaps. If you hear thunder, seek shelter even if the map looks clear; keep receiving official warnings.