THE millennium year had a sting in its tail, with a bitter, cold snap that began on Christmas Day. This hit the headlines, but it wasn't particularly icy and we experienced a similar spell before Christmas last year. The mildness during the first twelve days of December was quite exceptional, so that over the month as a whole, temperatures ended up about average, or a little above, notably at night.

It was yet another wet month with rainfall approaching one and a half times that expected* quite a modest excess when compared to recent months, when we were soaked by two to three times the norm.

The weather patterns familiar to us all this Autumn continued into December, with depressions always close by. As during the last few days of November, they mainly tracked north, close to western Britain, bringing us warm, southerly winds.

Later on the 12th, cold air moved in from the north-west. With clear skies the following night, many places had their first air frost of the season. This was surprisingly late, especially when the first ground frost was rather early, back at the beginning of September.

The barometer rose behind this cold front and by Saturday the 16th actually climbed above the mean for the first time in eight weeks. This rise in pressure helped stifle fronts approaching from the west. A few dry days resulted, and with clear skies, sharp frosts featured at night. The breeze also dropped off, allowing widespread, thick fog to blanket the region on the Monday, a wintry element we've been fortunate in escaping up until then with the changeable weather of late.

There has also been a lack of those gloomy, sunless spells we often get at this time of the year. However, a dull, overcast interlude followed over the next five days. This came about as a frontal system came to a grinding halt over us when high pressure asserted itself over Scandinavia. This anticyclone eventually declined as another built over Greenland. This enabled an arctic airstream to plunge south across Britain during Christmas Eve. Some woke up to a white Christmas with just a thin layer of snow. If not, within the next few days, almost everyone had experienced their first snowfall of the winter, with severe frost at night and the mercury remaining below freezing all day in many spots.

A deep depression moving north-east towards western Scotland pushed milder conditions back across the country for the New Year. But, before this battle was won, a blizzard accompanied by a southerly gale caused disruption to many revellers' plans on New Year's Eve.

December temperatures & rainfall at Carlton-in-Cleveland: mean maximum 6.8C, 44F, (*0.4C, *0.7F); mean minimum 2.7C, 37F, (+0.5C, +1F); highest 13.2C, 56F, 5th; lowest -5.9C, 21.5F, 28th; total rainfall 91mm, 3.6ins, (+25mm, +1.0ins); wettest day 17mm, (0.65ins), 5th; number of rain days, with 0.2mm (0.01ins) or more: 17 (+0.2). Figures in brackets show the difference from 17-year mean, 1983-99