October surprises with a sudden, wintry snap

Then, in the final few days, it shocked us with a sudden, unseasonably bitter, cold snap.

Typical of the region, here at Carlton, near Stokesley, the maximum on the 28th was the second lowest that I’ve recorded in any October in 25 years. It was just 0.5C (1F) above the peak of 5.7C (42.5F) on the 15th in 1992.

The remaining days of the month were only marginally milder, too. So, in the end, October was on the cool side and the chilliest since 2003. Incredibly, for some spots by the coast, it was the first colder than normal month for 2½ years.

Also in the east, it was well on course to be a dry month. Up until the morning of the 30th at Carlton, we’d collected little more than half our expected total. However, this was then substantially boosted by a rash of often beefy wintry showers, carried on-shore as the wind switched to a north-easterly.

Over one-third of the month’s accumulation fell in the last two days, but it still achieved that drier than usual status – just.

This is a rare event this year, with February and May the only other months to manage it so far.

Towards the Dales, significant downpours, conveyed on the earlier prevailing south-westerlies, made it a wet month. On the other hand, places sheltered from both directions, such as the Vale of Pickering, received barely two-thirds of their average rainfall.

We’ve had many cooler Octobers, notably 1993, no less than 2.5C (4.5F) colder. Even so, the 31st saw the first day in any October at Carlton on which there was snow lying at the official morning observation time. Actually, it was hail on the ground, not snow – but ice counts as well!

After the settled, mainly dry spell that started in mid-September, pressure was falling quickly as that month ended. The resulting changeable weather continued throughout October.

Deep depressions moved generally north-east between Scotland and Iceland every two or three days, steering those south-westerlies across Britain. They were strong at times, with gales in exposed parts, notably during the week from Sunday the 19th.

Rain on the associated fronts was often prolonged and torrential over the Pennines and particularly to their west, where there was occasional flooding.

To their east, it was chiefly light and patchy. The contrast was no more apparent than on Saturday the 25th when the severe conditions led to the chaotic abandonment of the Mountain Marathon in the Cumbrian Fells.

Showers between the rain-belts were also frequent in the west, too, where they ran in from off the sea. Being well into autumn, the sun has lost its strength and is unable to generate or sustain shower activity in-land. Hence, in the east, they were mostly negligible and very few and far between, yielding many, very pleasant sunny days – but, the tables were turned at the end of the month.

Around the final Sunday, pressure built northwards in mid-Atlantic.

This cut off the flow across that ocean and allowed winds, originating in the Arctic, to sweep southwards with a vengeance.

Their orientation across Britain kept to the west of north at first.

So, in the North-East, in the lea of the hills, we escaped the exceptionally early snow that affected other areas. We enjoyed some additional fine days but, despite the plentiful sunshine, it was distinctly cold with the first widespread air frosts of the winter.

Eventually, as the low slipped south and developed further in the western Mediterranean, the breeze veered to the east of north for the last couple of days, pulling in those abundant showers from off the North Sea.

October Temperatures and Rainfall at Carlton-in-Cleveland: Mean maximum: 12.7C, 55F (- 0.7C, -1F); mean minimum: 5.9C, 42.5F (-1.2C, -2F); highest maximum: 17.9C, 64F, 10th; lowest minimum: -2.5C, 27.5F, 29th; total rainfall: 58mm, 2.3ins (- 6mm, -0.25ins); wettest day: 16mm, 0.65ins, 4th and no of rain days, with 0.2mm (0.01ins) or more: 15 (-1). Figures in brackets show the difference from the 25-year mean, 1983-2007.