In Ottawa, the summers are long, warm, and partly cloudy and the winters are freezing, snowy, and mostly cloudy. Over the course of the year, the temperature typically varies from 6°F to 80°F and is rarely below -13°F or above 88°F.
Based on the tourism score, the best time of year to visit Ottawa for warm-weather activities is from late June to early September.
Ottawa lies farther north than Toronto, resulting in significantly colder winters.
Unlike many of Ontario’s cities, Ottawa does not sit on the shores of Lake Ontario. This results in higher summer temperatures in Ottawa but increases the harshness of the winters.
Ottawa has a semi-continental climate, with a warm, humid summer and a very cold winter.
Winters in Ottawa are severe. Snow depths of greater than 1 cm are seen on about 120 days each year compared with about 65 days in Toronto. Much greater depths of snow are also found in Ottawa than Toronto.
Ottawa, like other cities in Ontario, enjoys a sunny climate. Summers usually have a generous number of warm or hot sunny days.
Ottawa suffers less smog than Toronto. Air quality can be classed as very good, good, moderate, poor or very poor. In 2012, Ottawa had 29 days of moderate air quality. The rest were good or very good.
Ottawa’s day-to day-weather can be changeable throughout the year.