As North American mountain ranges go north-south, weather changes can be rather dramatic, with occasional snowstorms down into the South. As a general principle, the inland (which makes up most of the North American continent) has larger temperature difference between summer and winter than the coast.
The United States uses US customary units for weather reports, including degrees Fahrenheit (°F), and inches of mercury for air pressure.
Since 1970, Canada officially uses the metric scale (including degrees Celsius). Imperial units (including °F) are still in traditional use.
Near the US-Canadian border, US and metric units are used in parallel. See Metric and Imperial equivalents for details about unit conversions.
Most of Alaska and Canada have a boreal or sub-Arctic climate, with short summers and long, cold winters. The same applies for the tallest of the Rocky Mountains in the United States.
Southern Canada and most of the contiguous United States (except the south and southwest) have a temperate climate, where winters are short, but can be intensely cold.
The southwestern and southern United States (as well as northern Mexico) have a subtropical climate, where sub-zero temperatures are unusual, but not unheard of. Higher altitudes in these regions (the Appalachians in the southeast, and the various plateaus and mountains of the southwest) will often be much colder. A particularly dramatic contrast by altitude is in Arizona—in the state's capital of Phoenix, freezing weather is rare, but Flagstaff, less than three hours' drive to the north but about 5,800 feet/1,750 m higher, sees regular snowfall and low temperatures below freezing for over 200 days per year.
The tropics (Florida, southern California, Hawaii, the Caribbean and Central America) are warm year-round - except for higher altitudes which have less warm temperatures but also lack much temperature variation.
North America has colder winters than similar latitudes in Europe; on the US-Canada border (which mostly follows the 49th parallel) winter temperature is persistently minus 15 degrees C or colder; Paris and Vienna, which are nearly on the same latitude, are usually above zero. Churchill is roughly the same latitude as Stockholm, but can be 20 °C colder or more in winter.
The Great Lakes create a micro-climate zone; occasionally, the lands east of the lakes can see enormous amounts of snow.
The Pacific Coast has mild winters, with plenty of rain during the cold season. As far north as Vancouver, temperatures usually stay above zero. Nearby mountains are however cold and snowy at winter.
- See also: Winter driving
The United States and Canada are among the world's most car-dependent countries. Urban streets and major highways are usually plowed soon after snowfall; countryside roads are another story.
North America has many resorts for downhill snowsports; especially in the Rocky Mountains.
Christmas is a major holiday in the United States and Canada. A White Christmas is likely in most of Canada, except coastal British Columbia and southern Ontario.
While ice hockey in North America is associated with winter, the National Hockey League has gravitated towards the South in recent decades.
The need for precautions varies with location. Cities with regularly long and snowy winters (such as Winnipeg) tend to have better winter utilities than cities such as New York City, where snow and cold temperatures are less common.