To generalize, the weather in Ontario is considered to be a “continental” climate, but the reality is that because Ontario is such a huge province, the weather can vary immensely depending upon the season and location. In Ontario, temperature is reported in Celsius. Summers in southern Ontario can be extremely warm and humid with temperatures approaching 40ºC, whereas winters in Northern Ontario have been known to report very cold temperatures of -40ºC. These are examples of extreme temperatures, but most of the time the weather is more moderate, and people adapt to the various weather conditions quite easily once they know what to expect; preparation for the variations in weather conditions presented by each of the four seasons is essential. In spite of the weather, people continue to be active outside throughout all seasons.
Throughout Ontario there are four distinct seasons: spring, summer, fall and winter.
Spring (March to June): Tends to be a wet and rainy season where rainwear is necessary. Some parts of Ontario will continue to have snowstorms. Nights can be cool and temperatures can vary greatly during the day and from day-to-day.
Summer (June to September): Tends to warm up quickly and temperatures can be hot and humid and day are usually in the 20º-30ºC range while nights tend to average in the 10ºC range. Lightweight casual clothing with a hat and lots of sunscreen when outside are recommended.
Fall/Autumn (September to December): Tends to see days become much shorter with cooler temperatures, especially overnight. Trees start to get ready for winter by producing a “show” of colours. In parts of southern Ontario there tends to be rain and windy conditions, and in more northerly regions of the province there will be snow. Layered clothing works best to adapt to changes in temperature during the day so a sweater, lined jacket, and scarf are recommended.
Winter (December to March): Tends to have much shorter days, and there will be cold temperatures with frequent snowstorms. Sometimes there are special weather warnings about low temperatures that can be dangerous if people are not dressed appropriately for conditions. Gusting winds can make temperatures feel much colder than the reported air temperature. Therefore, it is absolutely essential that a winter coat, a hat, and sturdy boots be worn in order to stay warm. Again, dressing in layers is beneficial to deal with the weather conditions.