dooi

Dooi is the Dutch term for a thaw, the period in which temperatures rise above freezing after a cold spell and ice and snow begin to melt. The phenomenon is common in late winter and early spring, but can also occur in autumn in milder years. The driving forces are typically a combination of warming air masses from the southwest, higher solar radiation, and changes in atmospheric pressure, which can bring milder weather and raindays.

During a dooi, meltwater increases runoff, which can raise water levels in rivers, canals, and urban drainage systems. Snow cover may quickly shrink, and ice on waterways can break up, affecting navigation and increasing the risk of floods and ice jams. The rapid change between freezing and above-freezing temperatures can also pose hazards to pedestrians and motorists due to slippery or slushy surfaces.

In Dutch weather forecasting, dooi is a standard term used to describe the thawing period; it is often accompanied by phrases like 'dooi doorbreekt de vorst' or 'De dooi komt eraan.' The term is primarily used in the Netherlands and Belgium, though similar thaw events occur in other temperate regions under comparable meteorological conditions.

While a dooi can bring relief from persistent cold, it can also be followed by renewed freezing if a cold air mass returns, leading to a new set of hazards on ice and roads.