What Is a Cold Snap?
A cold snap is a period of unusually cold weather that lasts for a relatively short time. Temperatures fall noticeably below what is typical for the location and season before eventually returning closer to normal.
There is no single temperature that defines a cold snap everywhere. A temperature considered unusually cold in southern Ontario, for example, may be relatively normal during winter in northern Canada.
Cold snaps can last from a few days to longer periods and may bring freezing temperatures, dangerous wind chills and increased risks from exposure to the cold.
Related Conditions
| Condition | Description |
|---|---|
| Arctic Outbreak | The southward movement of a large mass of very cold Arctic air. |
| Cold Wave | A prolonged period of unusually cold weather affecting a region. |
| Deep Freeze | An extended period when temperatures remain well below freezing. |
| Arctic Air Mass | A large body of extremely cold air that develops over Arctic and polar regions. |
| Cold Front | The leading edge of an advancing mass of colder air that can cause temperatures to fall quickly. |
Related Alerts
| Alert | Description |
|---|---|
| Extreme Cold Warning | Warns when very cold temperatures or wind chill create dangerous conditions. |
| Wind Warning | Issued when strong winds are expected to reach warning criteria and create hazardous conditions. |
| Winter Storm Warning | Warns of a significant combination of hazardous winter weather. |
| Snow Squall Warning | Warns of snow squalls that can cause sudden poor visibility and hazardous travel. |
| Blowing Snow Advisory | Issued when blowing snow is expected to significantly reduce visibility. |
What Causes a Cold Snap?
A cold snap develops when a colder air mass moves into an area and replaces the milder air that was previously in place. Changes in atmospheric pressure and wind patterns determine where this cold air travels and how long it remains.
Cold fronts are one way colder air can arrive. As a cold front passes, winds can shift and temperatures may fall quickly as colder air moves in behind it.
Some of the strongest cold snaps occur when very cold air moves south from northern Canada or the Arctic. A large southward movement of this air can develop into an Arctic outbreak affecting a much larger area.
Clear skies and light winds can sometimes allow temperatures to fall even further overnight because heat from the ground escapes more readily into the atmosphere.
Wind can make a cold snap more dangerous even when the actual air temperature does not change. Stronger winds increase heat loss from exposed skin, producing lower wind chill values and increasing the risk of cold-related injuries.
The cold weather usually ends when the atmospheric pattern changes and milder air begins moving back into the region.
FAQ
There is no universal temperature. A cold snap is defined relative to what is normal for a particular location and time of year.
Both describe unusually cold weather. A cold snap generally refers to a relatively short period of cold, while a cold wave typically describes a more prolonged or widespread period.
A cold snap describes a period of unusually cold weather. An Arctic outbreak specifically involves a large mass of very cold Arctic air moving south into lower latitudes.
Yes. Wind increases heat loss from exposed skin and can produce much lower wind chill values than the actual air temperature.