The five-day Christmas weekend forecast calls for extra-thick socks and six layers of mittens, but current indications are that December 25 will be white.
Friday night to Saturday morning will see temperatures ranging from -19 to -14 C and dipping as low as -21 C in the northeast, according to the elves manning the Meteorology and Hydrology Institute.
The presence of a couple of high-pressure systems, however, will mean the weekend will start with a break-up of Friday's cloud cover, and there will be a mixture of clear spots and light snow in places. Daytime temperatures on Saturday should climb into the -17 to -12 C zone, but will plummet back into the -20 to -15 C zone overnight.
Clearer, drier weather is in the cards for Sunday, with both daytime and nighttime thermometer readings much the same as Saturday's.
Christmas Eve is expected to be peaceful and frosty. Snow is forecast, starting from the islands and moving inland through the day, as a low-pressure system on the Baltic Sea brings strengthening winds and whirling snow that will give Santa a rough ride. Daytime temperatures are forecast to be -16 to -11 inland and -12 to -7 on the islands, but should actually rise by a couple degrees at night as things warm up, relatively speaking, for Christmas.
Thanks to a low-pressure front sent as a gift from Sweden, Christmas should be snowy and blustery. Air temperatures will warm up to around 0 C on the islands and -5 to 0 C on the mainland, though it could stay down near -10 C in the northeast. At night, changing weather patterns will push temperatures above the freezing mark in places.
Wednesday, Boxing Day, is expected to bring a further thaw and along with it, slippery roads. Drivers and anyone carrying home a crystal vase are advised to take caution. Snow and sleet in the early morning could turn to rain and sleet during the day, with strong winds blowing throughout. The daytime temperatures will be 0 to +3 C and will only get down to the -3 to +1 C range at night, creating prime conditions for icicle growth.