Freeze-thaw events
In Quebec, freeze-thaw events occur mostly in the spring and fall, but sometimes in winter.
The number of freeze-thaw events varies considerably from region to region in the province and depending on the time of year.
Freeze-thaw cycles can have a variety of negative impacts, such as on infrastructure like buildings and roads, and they can be critical for agriculture and other biological systems.
The definition of a freeze-thaw event can vary depending on the field of application. For example, the freezing and thawing of the ground is important in many cases.
However, most climatology studies on freeze-thaw events look at the air temperature at about 2 meters from the ground, as this observational data is the most widely available and is best represented by climate models.
Definition | Freeze-thaw event (or cycle)
A freeze-thaw event occurs when the air temperature (about 2 metres above the ground) alternates above and below 0°C, the freezing point of water, over a 24-hour period. This variable is expressed as the number of freeze-thaw days per month, season or year.
Note: Ouranos’ projections and the information shown on this page are based solely on this definition. It remains an excellent proxy for other phenomena, such as the freezing and thawing of the ground.
