Significant Weather Events in Niagara
There are no significant weather events in Niagara at this time. A map and information will appear when a weather event is in progress.
Weather definitions
Local snow accumulations may be significant.
- Blizzard
When winds of 40 km/hr or greater are expected to cause widespread reductions in visibility to 400 metres or less, due to blowing snow, or blowing snow in combination with falling snow, for at least four hours.
- Blowing snow
When blowing snow, caused by winds of at least 30 km/hr, is expected to reduce visibility to 800 metres or less for at least three hours.
- Extreme cold
Issued when the temperature or wind chill is expected to reach minus 30 C (degrees Celsius) for at least two hours.
- Snow fall
When 15 cm or more of snow falls within 12 hours or less.
- Snow squall
When, down wind of large bodies of water, like the Great Lakes, snow squalls are imminent or occurring with one or more of the following conditions being produced:
- Localized, intense snowfall producing snowfall amounts of 15 cm or more in 12 hours or less
- Reduced visibility (less than 400 metres) caused by heavy snow with or without blowing snow for three hours or more
- Flash freeze
When significant ice is expected to form on roads, sidewalks, or other surfaces over much of a region because of the freezing of residual water from either melted snow, or falling / fallen rain due to a rapid drop in temperature.
- Freezing rain
When freezing rain is expected to pose a hazard to transportation or property or when freezing rain is expected for at least two hours.
- Freezing drizzle
When a period of freezing drizzle is expected for at least eight hours.
- Winter storm
When severe and potentially dangerous winter weather conditions are expected, including:
- A major snowfall (25 cm or more within a 24 hour period)
- A significant snowfall (snowfall warning criteria amounts) combined with other cold weather precipitation types such as: freezing rain, strong winds, blowing snow and / or extreme cold
- Blizzard conditions may be part of an intense winter storm, in which case a blizzard warning is issued instead of a winter storm warning
