Climate in Canada varies widely from region to region. In many parts of the country, particularly in the interior and Prairie provinces, winters are long, very cold, and feature frequent snow. Most of Canada has a continental climate, which features a large annual range of temperatures, cold winters, and warm summers. Daily average temperatures are near −15 °C (5 °F), but can drop below −50 °C (−58 °F) with severe wind chills. In non-coastal regions, snow can cover the ground for almost six months of the year, while in parts of the north snow can persist year-round. Coastal British Columbia has a more temperate climate, with a mild and rainy, cloudy winter. The British Columbia Southern interior has a semi-desert climate in many locations, with long warm to hot, dry summers, and short moderate winters. The immediate area adjacent to the town of Ashcroft, features Canada's only true desert. On the east and west coasts, average summer high temperatures are generally in the low 20s °C, while between the coasts, the average summer high temperature ranges from 25 to 30 °C (77 to 86 °F), with temperatures in some interior locations occasionally exceeding 40 °C (104 °F).
Much of Northern Canada is covered by ice and permafrost; however, the future of the permafrost is uncertain because the Arctic has been warming at three times the global average as a result of climate change in Canada. Canada's annual average temperature over land has warmed by 1.7 °C (3.1 °F), with changes ranging from 1.1 to 2.3 °C (2.0 to 4.1 °F) in various regions, since 1948. The rate of warming has been higher across the North and in the Prairies. In the southern regions of Canada, air pollution from both Canada and the United States—caused by metal smelting, burning coal to power utilities, and vehicle emissions—has resulted in acid rain, which has severely impacted waterways, forest growth and agricultural productivity in Canada.
