The information on this page is therefore not derived from first-hand experience. It has, however, been obtained from reliable sources. I would advise anyone intending to travel in Canada or the northern or mountainous parts of the USA in winter to obtain local information for the area they will be visiting in advance, and to regularly check local weather forecasts while on the road. Conditions are often unpleasant and can be extreme. Local radio and television stations also carry warnings of bad weather conditions and road closures.
Temperatures can often fall far below freezing for long periods.
Snowfalls can be considerable - blizzards and snowdrifts are not uncommon. The climate tends to be less extreme on the coasts, both in summer and winter. Temperatures naturally tend to be much lower as you go further north or higher in altitude. Winter driving conditions naturally tend to be more extreme in the mountains and on the open expanses of the Great Plains . Some roads over mountain passes are closed throughout the winter, although all the Interstates and major US Highways and even many state highways remain open except when they are blocked by snowfall during periods of extreme weather.