UNSETTLED weather had dominated November and with the air-flow from a southerly quarter for virtually the entire month, it was mild, wet and with no sign of winter. This continued for a few days in December with frontal systems crossing the country from the south-west. However, there was already a hint of a change as they became slow moving to the east of Britain.

High pressure, as far away as northern Russia, was starting to make its presence felt. Eventually, a ridge from the high nosed south-west towards Scotland, pushing remnants of the last front back westwards later on the 5th. Winds, having become very light, picked up from the east, as a bitter air-mass reached us via northern Europe from Siberia.

Those who watch their barometers must have wondered what was going on. Pressure soared to well above the highest level for many months, into the "Very Dry" section on the dial. Yet, especially near to the coast on the 6th and 7th, it was still pouring with rain from time to time.

The centre of the high was still more than 1,000 miles away over northern Scandinavia at 1060mb (31.3ins), well off the top of the scale of most wall barometers. This was about 25mb (ins) higher than over us, so here, pressure was still relatively low. Thermals from the comparatively warm North Sea rose readily into the very cold air, producing thick cloud and the showery rain. Much drier air arrived at the start of the second week for a few days, providing some good, sunny periods.

High pressure usually builds over Russia during winter, occasionally extending into Scandinavia. The highest known atmospheric pressure is 1084mb (32.0ins) at Agata, Siberia, on New Year's Eve, 1968. In the UK, it is a modest 1055mb (31.1ins) at Aberdeen on January 31, 1902. In contrast, the lowest recorded pressure at sea level is 870mb (25.7ins) measured in the centre of a typhoon in the Pacific, west of Guam, in October 1979, whereas in the UK, 925mb (27.3ins) was registered near Crieff, Tayside, in January 1984.

Temperatures declined every day from the start of the month until the 12th but never fell very low in our region. It is a complete myth that northern Britain is always colder than the South - especially in this weather situation. Over much of Northern Europe, the mercury hovered typically around -10C (14F). Fortunately, thanks to the long sea track, in the order of 400 miles between us and Denmark or northern Germany, it remained mostly above zero (32F) over us. The Channel Islands were actually the coldest spots in the British Isles on a few occasions during this "freeze-up" - not unusual when there's an easterly in winter, as there's only 15 miles between Jersey and mainland France.

Mind you, it felt well below freezing in the brisk breeze that got up at times, especially during that brighter spell. This was a "lazy" wind, as I understand it - one that cuts straight through you, rather than going round. With the high now declining, milder conditions tried to invade again from the south-west. The process was very slow, yielding more leaden skies, mist and persistent drizzle.

There were some heavy bursts of rain, too, as a low moved up the Channel on Sunday the 15th, but as it moved away, another anticyclone developed over the north-west of Scotland. This brought another welcome, dry, sunny interlude. With the clear skies and as it became calm, sharp frosts resulted during the next two nights. Up to this point in the month, I hadn't recorded a single air frost here at Carlton, near Stokesley.

Unfortunately, this high moved away east, allowing the wind to slowly veer into the south, so that by the weekend before Christmas, Atlantic air had once more engulfed the country. The rest of the month was very unsettled, mostly mild, wet and blustery at times.

Colder air returned briefly from the east during the last couple of days as a depression moved north-east across southern Britain. The clash of airstreams generated the wettest day of the month in our area on the 29th, with local flooding and some snow on the highest moors.

Overall, the month was on the mild side, the warmest since December 1998. This was despite the days being cooler than usual, but mean minima were the third highest in December, after those in 1988 and 1987, in my 20 years of data. This was due to nights being generally cloudy and breezy, preventing temperatures taking a dive. The 29th was the main cause of it being rather wetter than expected.

The year was not very remarkable, apart perhaps from the warmth from mid-January to mid-February, the sunny spring, the April and September dry spells and the deluge on August 1. However, the consistent mildness, with the exception of July and October, made it one of the warmest in my logs - admittedly, only the fourth, but the top four are all within a whisker of each other (0.1C, 0.2F).

Rainfall over the region was, in the main, fractionally above the norm. Even so, here at Carlton, it was the driest for five years, though towards the Pennines it was rather wetter with up to 25pc more than average.

DECEMBER TEMPERATURES &

RAINFALL at CARLTON IN CLEVELAND

Mean max 6.5C, 44F, (-0.6C, -1.1F)

Mean min 3.2C, 38F, (+1.2C, +2.2F)

Highest max 11.5C, 53F, 24th

Lowest min -3.8C, 25F, 18th

Total rainfall 82mm, 3.3ins, (+15mm, +0.6ins)

Wettest day 28mm, 1.1ins, 29th

No of rain days, with 0.2mm (0.01ins) or more: 20 (+3.5)

(Figures in brackets show the difference from the 19-year mean, 1983-2001