December 2004 was slightly milder and drier than average. There were 17 consecutive days from the 29th November to 15th December without measurable rainfall, the longest dry spell at this time of year since 1991 (18 days). The first half of the month saw the continued persistence of high pressure to the SE; with the consequences of no rainfall, light winds, little sunshine and a great deal of anticyclonic gloom. The first air-frost of this autumn/winter was recorded on the 11th - the first sub-zero here since the 3rd March. Visibility was poor to moderate with frequent haze or mist and occasional dense fog.The second half of the month begins with the return of Atlantic weather systems pushing across the country, and a vigorous depression brings gales and the first heavy rainfall since the 18th November. A further deep depression brought wind, rain and mild conditions on the 22nd, but although it turned colder on the night of the 24th, there was no "white Christmas" with cool, bright and dry weather prevailing. There was a heavy ground frost on Boxing Day morning and the weather turned from cool to very mild at the end of the month.