A severe thunderstorm watch has been issued by Environment Canada for Waterloo and northern portions of Wellington County.
The agency says that conditions will arrive in the early afternoon which could develop into severe thunderstorms.
It says the conditions will persist into tonight.
Environment Canada warns the area could see wind gusts up to 100 km/h, nickel size hail, localized heavy rainfall and there is also the potential for a tornado.
The agency says it issues these type of watches when atmospheric conditions are favourable for the development of thunderstorms which could lead to large hail, damaging winds and/or torrential rainfall.
It says the Office of the Fire Marshal and Emergency Management recommends residents find cover right away if threatening weather is approaching.