Live precipitation radar centred on Calgary. Radar shows you what is falling right now and which way it is moving — which makes it the fastest way to answer "will this reach me, and how long have I got".
Colour is intensity, not type. Blues and greens are light rain or snow; yellow, orange and red are progressively heavier. The heaviest cores in a summer thunderstorm show as tight red or magenta blobs, and those are the cells worth taking seriously.
Direction matters as much as colour. Calgary's summer storms usually track from the southwest or south toward the northeast, so a red cell sitting southwest of the city in mid-afternoon is the classic setup for a storm crossing town within the hour. Watch two or three frames to judge speed before deciding you have time.
Radar detects precipitation, and very heavy returns often do indicate hail — but a bright red core is not proof of hail, and hail can fall from a cell that looks less dramatic. Reliable hail detection needs dual-polarisation products and forecaster interpretation, which is what Environment and Climate Change Canada does when it issues a severe thunderstorm warning.
This site approaches the question from the other side: it grades hail possibility for the next ~12 hours per district from the forecast model's instability and precipitation fields, rather than trying to infer it from radar returns. Use them together — the model risk to plan your afternoon, the radar to see what is actually approaching. More on how hail works here in the Calgary hail season guide and Hailstorm Alley explained.
Radar tells you what is coming; it does not tell you the temperature, wind, air quality or hail grading where you are. For that, open the live neighbourhood map and click your community — or go straight to a district: Downtown, northeast, southwest or northwest.
Radar imagery is supplied by RainViewer. Nothing on this page is an official weather warning — follow Environment and Climate Change Canada and Alberta Emergency Alert for safety decisions.