Hail Watch vs Warning in Calgary

A watch means get ready: conditions favour severe thunderstorms that could bring hail. A warning means act now: severe weather is happening or about to happen. For your car, a watch is the time to decide where it will sit. A warning is the time to get it there, if you can arrive before the storm does.

The short answer: watch vs warning, and what to do on each

Environment and Climate Change Canada (Environment Canada) uses two levels, and hail risk shows up in its severe thunderstorm watches and warnings.

Watch: get ready. Conditions are favourable for severe weather. Nothing may happen, but the ingredients are there.

• Decide where the car will be through the afternoon and evening.
• If covered parking is close, consider moving early while the sky is still clear.
• Put a cover or blankets in the trunk if you use them.
• Make sure alerts are on (more on that below).

Warning: act now. Severe weather is happening or about to happen.

• Move the car under a roof now, if you can get there before the storm.
• If the storm is already between you and shelter, stay put.
• Fit a cover only if you can finish before the hail starts.
• Once hail is falling, stay inside.

Plan on a watch, move on a warning, and never go out into the hail itself. Where to go is ranked in where to park when a Calgary hail warning hits.

Where Calgary hail alerts come from

Weather watches and warnings in Canada come from Environment Canada, and it recommends its own WeatherCAN app for forecasts and alerts. For hail, that is the tool to set up properly.

Three settings worth getting right:

• Turn on notifications for alerts, not just the forecast.
• Set it up for where your car actually sits, which may mean a workplace or school as well as home.
• Check it is not silenced. A do-not-disturb or focus mode you forgot about can swallow the one alert that matters.

Why bother when your phone already blares for emergencies? Because for most hail, it will not.

Why most hail warnings will not interrupt your phone

Alert Ready is the system that breaks into TV, radio and phones with an emergency alert. It is used for tornado warnings, and for severe thunderstorm warnings only when winds of 130 km/h or more or baseball-size (7 cm) hail are expected.

That is a high bar. Most hail warnings sit below it, so most hail warnings will not set off that loud phone alarm.

The same bar applies to TV and radio. Below it, Alert Ready will not break into the show you are watching or the station you are driving with. A station may still mention the warning, but you cannot count on hearing it.

What that means in practice:

• Silence is not safety. No emergency alert does not mean no hail warning.
• An app with notifications on is how you hear about ordinary hail warnings. WeatherCAN is the one Environment Canada points to.
• If an Alert Ready message does arrive for a thunderstorm, the storm meets that top tier. Act immediately, and put your own safety well ahead of the car.

The 2026 change: polygon warnings

In August 2026, Environment Canada announced that severe thunderstorm and tornado warnings would be issued as polygons, shapes drawn around the area most likely to be affected, with the change rolling out gradually.

For Calgary drivers, that means a warning shows a shape on the map around where the storm is most likely to hit. Being inside the shape is a strong reason to act. Being just outside it is a reason to keep watching, not to relax.

The catch is how phones handle it in WeatherCAN:

• Android phones alert only when you are inside a polygon.
• Apple devices may also alert for warnings "nearby".

Your phone and your car are not always in the same place. If you are at work across the city and the car is at home, or the other way round, do not rely on a ping. When a watch is out, open the app and check the warnings for wherever the car is parked.

Knowing a warning exists is half of it. The other half is how much time it leaves you.

How much notice will you get?

Do not plan around a fixed number. Environment Canada says warnings are usually issued 6 to 24 hours in advance and can be longer, but that is a general statement about weather warnings, not a figure for hail or thunderstorms in particular. The same source notes that some severe weather, such as tornadoes, can arrive with less than 30 minutes' notice.

So treat the watch as your planning window, and treat a warning as a now-or-never call. If getting to covered parking takes a while, the watch is your cue to go.

It also helps to know when to expect any of this. When Calgary's season tends to run, and why the city sits in Hail Alley, is covered in what to expect from Calgary hail season. IBC says Alberta has had at least one major hailstorm every year for two decades, so this is a plan you will use.

If you rely on a cover

A cover only helps if it is on before the hail. That makes the watch your real deadline, not the warning.

• Time your setup once on a calm day, from trunk to fully strapped.
• If that time is tight, fit it on the watch and take it off if the storm misses.
• Inflatables add steps. Power, inflation and extra wind exposure all eat into your window. The trade-offs are in are inflatable car hail protectors worth it.
• Never fit one while hail is falling. Environment Canada says hailstones can reach grapefruit size.

Whatever protection you used, the job is not done when the warning ends.

After the warning ends

Wait until the storm has passed and it is safe to go out. Then:

• Check glass and lights first. Cover any broken glass before the next rain.
• Photograph every panel in soft, angled light, before you wash the car. Bright overhead sun hides shallow dents.
• Know how it is claimed. Hail goes under comprehensive (or all perils), not collision, and Alberta's statutory conditions ask for prompt written notice of a loss.

The full first-48-hours checklist, in order, is in what to do after a Calgary hailstorm.

If the panels look clean but you are not sure, that is worth a proper look before the next season starts.

Get a baseline before the next warning

If the car already carries dents from a past storm, or you want a clean record of it before next summer's first watch, book the free 30-minute scan at the shop in SE Calgary. A technician checks every panel under proper lighting and tells you what is there and what can come out without paint. Rather start from home? Send a few photos taken at a low angle with light running across the roof and hood.