JANUARY started dry, cold and frosty but soon turned very mild, wet and windy - but on this side of the Pennines, we weren't soaked too much.

Air frosts occurred widely on each of the first seven days but then only once more during the rest of the month. The warmth had more than made up for the early chill by mid-month, and overall, it became the mildest January since the exceptional ones of 1989 and 1990. Both of these were about 1C (2F) warmer than this year's - neither had an air frost. In January 2002, we had just one day with snow falling here at Carlton in Cleveland, near Stokesley - in that of 1989, not a single snowflake fell.

There was negligible rainfall during the first ten days. Even after this, as it became increasingly changeable, there were never any large, daily totals, at least towards the east coast. Generally, the month's accumulations were about half the norm and it was the driest January since 1997, when I measured a mere 12mm fell (less than half an inch). However, towards the Pennines, rainfall was nearer the average, and on their western slopes, it was very wet, giving rise to the risk of flooding from many rivers.

The northerlies that gave the wintry end to last year were soon replaced by a southerly flow as a high-pressure cell moved east across the country on the 1st. It remained distinctly chilly for a few more days since the source of the wind was from France, still icy-cold from their December freeze-up. Following the passage of a front on the 5th, the airstream blew in from the Atlantic and a rapid thaw of remaining snow set in. As well as being milder, it was also more humid, and with still both very light winds and a cold ground, fog became a problem in low lying areas, particularly the Vale of York.

This was finally blown away towards the end of the second week, as a mobile weather-type became established, with a regular procession of frontal systems moving east or north-east over the British Isles. These brought cloudy spells, but initially, with high pressure not too far away over the continent, rain from them was mostly light and patchy, and between, there were good sunny periods. With the airstream often originating from well south in the Atlantic, it became very warm, the mercury exceeding 10C (50F) on several days - quite spring-like.

By the fourth week, the associated depressions themselves were approaching ever nearer with, eventually, a couple crossing northern Britain. A few were intense, producing strong winds at times and gales in exposed places on the 20th, and notably on Monday the 28th, when many lorries were toppled and trees blown down across our region.

The Meteorological Office defines a gale as a wind reaching more than 34 knots (39mph) at 10m (33ft) above the ground for at least ten minutes. At this speed, twigs break off trees, walking is difficult and umbrellas are blown inside out. A true gale is rare in low-lying, inland parts, occurring typically only once in a few years. Gusts, of course, reach these velocities more frequently, as they can be at least double the mean speed.

Winds vary considerably from place to place, even just yards apart, at any one time. This depends on local geographical features, such as hills, building and trees, height and atmospheric conditions. On the small scale, we've all experienced this as we walk around a town with tall office blocks, in a calm one minute, being almost blown off our feet the next.

JANUARY TEMPERATURES

AND RAINFALL

AT CARLTON IN CLEVELAND

Mean max 8.2C, 47F, (+1.9C, +3.5F)

Mean min 2.6C, 36.5F, (+1.4C, +2.5F)

Highest max 12.6C, 54.5F, 21st

Lowest min -5.6C, 22F, 1st

Total rainfall 30.5mm, 1.2in, (-32mm,

-1.25in)

Wettest day 7.5mm, 0.3in, 25th

No of rain days, with 0.2mm (0.01in) or more 12 (-5)

(Figures in brackets show the

difference from the 18-year mean, 1984-2001