The temperature varies greatly from one season to another, you should prepare your luggage accordingly. You should also take in to account of the regions you plan to visit. For example, summer more humid in the Montreal area than elsewhere in Quebec and the winter is slightly longer in the East than in the Southwest.
In summer (mid-June to mid-September), the days are hot and sometimes humid. Montreal has heatwaves every summer. Light clothing is therefore required, but be sure to bring a jacket and trousers for evenings and for the few cooler days. Warm clothing is also needed for trips in the estuary and Gulf of St. Lawrence (the wind can be very cold) and for mountain expeditions.
During the fall (mid-September to mid-December), the mercury slowly decreases to make room for the winter. The months of September and October are very pleasant, even if the weather is cooler in summer. A windbreaker is a choice and a raincoat, since the days of rain are more frequent. Starting in November, the mercury around the freezing point and the risk of increasing snow precipitation (from early November to the east of Quebec). In this case, it is necessary to wear a coat, boots, scarves and gloves
In winter (mid-December to mid-March), temperatures typically range from -15 ° C and -20 ° C. However, sometimes the mercury drops considerably. Outdoor activities require special clothing: snow pants, warm coat, boots, hat, mittens, etc.. During cold weather or long expeditions, there are simple ways to keep warm, particularly hot hands in the form of packet, which fit equally well in boots than in the mitts. Even in the city, it usually include a pair of boots to get around the snowy streets.
In spring (mid-March to mid-June), the heat is gradually returning. The mercury reached O ° C in March. Slowly, the snow melts and nature wakes up. The warm weather settles in June, where there was easily 20 ° C, but it is usually preceded by several episodes of summer time in May and sometimes even at the end of April.