17th February 2018,
Long-term prevailing weather patterns divide the climates of the North East of England and Yorkshire from those of the North West. Nowhere more is this illustrated by the average annual rainfall totals and when the wettest months occur.
The prevailing wind-direction in this country is from the south-west (westerly in the spring and early summer). This is because high-pressure, that brings fine weather is usually well to the south of Britain whilst North Atlantic depressions, that bring wet and windy weather, race eastwards between Iceland and Scotland. Thus it is wetter the further north you go, but the west side of the country is much wetter than the east as well. The first thing moist south-westerlies hit on reaching northern England are the coasts and hills of Cumbria, Lancashire and Merseyside. As air is forced upwards over hills it cools and drops its moisture content as rain (or sometimes in winter, snow). The air, relieved of much of its moisture then descends in the lee of the Pennines and warms a little: Consequently the lowlands of the North East of England and of Yorkshire are, on aggregate, much drier than locations at similar elevation in North West England.
The depressions that usually pass to the north of Scotland are more intense in late autumn and early winter; thus for locations in the North West of England, October or November is normally the wettest month: However further east and east of the Pennines August tends to be wetter because the fact that the air is warm and moist and the Sun is strong leads to more thundery-type rainfall then.
Let us now provide a breakdown of mean annual rainfall and the wettest month for selected towns and cities in Cumbria, the North West outside of Cumbria and then the North East locations:
Barrow-in-Furness: 95.6 cm mean annual rainfall, wettest month November.
Seathwaite (Borrowdale): 330.0 cm mean annual rainfall, wettest month January.
Whitehaven: 97.1 cm mean annual rainfall, wettest month October.
Carlisle: 82.2 cm mean annual rainfall, wettest month September.
NORTH EAST ENGLAND
Newcastle: 65.5 cm mean annual rainfall, wettest month August.
Durham: 64.1 cm mean annual rainfall, wettest month August.
Berwick-upon-Tweed: 69.9 cm mean annual rainfall, wettest month August.
Middlesbrough: 64.6 cm mean annual rainfall, wettest month August.
NORTH WEST ENGLAND (Excl. CUMBRIA)
Manchester: 86.7 cm mean annual rainfall, wettest month August.
Liverpool: 83.6 cm mean annual rainfall, wettest month November.
Preston: 104.4 cm mean annual rainfall, wettest month December.
All the principal North East cities and towns have annual rainfall totals less than 70 cm per annum on average but all the North West cities (outside Cumbria) had at least 83 cm mean annual rainfall and with the wettest month being late in the year on average . For Cumbria Carlisle is the driest with over 82 cm rainfall in an average year with September the wettest month. The other Cumbrian locations have over 95 cm of rainfall per annum with October or November the wettest month.
Seathwaite, high up on the Lakeland Fells to the south of Keswick is in a class of its own with a mean annual rainfall of 330 cm. It has the wettest climate of England and the wettest month at Seathwaite is infact January.
The climate of locations in Cumbria, even around Carlisle, are really wetter versions of the climates of other parts of North West England. The heaviest rains tend to occur in late autumn or early winter- as those in Cumbria who lived through the devastating floods of November-December 2015 would attest! Only further inland, with some shelter from hills do rainfall amounts drop off and summer convection-type rainfall gets to be more important (Manchester actually is wettest in August and Carlisle is wettest in September).
The climate across the North East lowlands is significantly different with rainfall totals over 12 cm less than in the North West cities. The highest rainfall totals there are in late summer.
The one county of the North West of England with a climate more like the North East lowlands is Cheshire- at least the western half of the county where the Welsh Mountains protect the area from rainy south-westerlies in autumn and winter.
Certainly from a climate-related perspective north and (especially) west Cumbria should be getting Regional Television from the North West. At present the weather-presenter on the BBC Look North news broadcast from Newcastle to northern Cumbria has to provide a forecast for very different climatic zones across the North East /Cumbria broadcast area.
The Meteorological Office certainly treats Cumbria as part of North West England as its North West England and North Wales Region includes the county. That’s likely to be because Cumbria has a similar climate (if wetter and a little colder) to other areas of North West England.
References from https://en.climate-data.org