High season in the cities is late May through early September, and, in Québec City, February weekends during the big winter Carnaval. The period from Christmas to New Year's is also busy. Hotels are most likely to be full and charge their highest rates in these periods. Low season is during March and April, when few events are scheduled and winter sports start to be iffy. The late-fall months of October and November are also slow, due to their all-but-empty social calendars.
Weather -- Temperatures are usually a few degrees lower in Québec City than in Montréal. Spring, short but sweet, arrives around the middle of May. Summer (mid-June through mid-Sept) tends to be humid in Montréal, Québec City, and other communities along the St. Lawrence River, and drier at the inland resorts of the Laurentides and the Cantons-de-l'Est. Intense, but usually brief, heat waves mark July and early August, but temperatures rarely remain oppressive in the evenings.
Autumn (Sept-Oct) is as short and changeable as spring, with warm days and cool or chilly nights; it's during this season that Canadian maples blaze with color for weeks.
Winter brings dependable snows for skiing in the Laurentides, the Cantons-de-l'Est, and Charlevoix. After a sleigh ride or a ski run in Parc du Mont-Royal, Montréal's underground city is a climate-controlled blessing. Outside, snow and slush are present from November to March.
