Monthly Weather Review January 2011

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  • Monthly Weather Review January 2011
    31.01.2011 13:23

     

    The main features of the month were:

    Cold and wintry in Scotland till the 11th

    Exceptionally mild but very wet 12th-16th

    Overall rather dry and sunny in Scotland and Northern Ireland

    Overall dull and wet in southeast England

     

    January opened with a few days of anticyclonic weather, followed by a week of cyclonic conditions and then a week of southwesterlies. The second half of the month was mainly anticyclonic. Rain fell frequently and sometimes heavily between the 7th and 17th, but amounts of rain during the remainder of the month were generally small. Apart from a very mild spell between the 12th and 16th, the weather was mostly rather cold.

    Mean maximum temperature for January ranged from 8.8°C at St Mary's (Isles of Scilly) to 3.3°C at Dalwhinnie (Inverness-shire) and Carter Bar (Roxburghshire), while mean minimum temperature varied between 6.4°C at St Mary's and minus 2.1°C at Braemar (Aberdeenshire). Both mean maximum and mean minimum temperatures were 0.0-1.0degC above normal in the eastern half of England, but 0.0-1.0degC below in all other parts of the UK. The Central England Temperature (CET) of 3.9°C was 0.3degC below the long-term mean, but was higher than the last two Januarys.

    The highest maximum at a standard site (i.e excluding rooftop and mountain sites) in the UK was 14.5°C at Pershore (Worcs) on the 13th, while the lowest minimum was minus 13.0°C at Altnaharra (Sutherland) early on the 8th. The lowest daytime maximum was minus 3.9°C at Strathallan (Perthshire) on the 7th, and the warmest nights were those of the 12th/13th and 15th/16th with a minimum of 11.8°C at Exeter (Devon) and Linton-on-Ouse (N.Yorks) respectively.

    Rainfall averaged over England and Wales (including a very small estimated figure for the 31st) was 82mm which is 88 per cent of the average for the standard reference period 1971-2000, rather higher than January 2010 but slightly lower than January 2009;  in the last 100 years 36 Januarys were drier while 64 were wetter. The equivalent figures for Scotland were 79mm and 80 per cent of the normal amount, and for Northern Ireland 50mm and 53 per cent. Monthly totals at routinely-available sites ranged from 278mm at Capel Curig (Caernarfon) to 14.4mm at Dishforth (N.Yorks).

    Sunshine averaged over England and Wales (including an estimated figure for the 31st) during January was 55 hours which is exactly 100 per cent of the 1971-2000 mean.  The equivalent figures for Scotland were 55 hours and 131 per cent, and for Northern Ireland 77 hours and 159 per cent.  Largest total in the UK was 77 hours at Camborne (Cornwall) although Belmullet in the IrishRepublic recorded 87 hours, and the smallest was just 26 hours at Lerwick (Shetland).

    It was another quiet month with few gales. The windiest days of the month were the 15th and 16th with gusts to 66kn (76mph) at Capel Curig (Caernarfon).

    Snow from December's falls remained on the ground in upland parts of Scotland and northern England until the 12th or 13th. Amounts of fresh snow during January were generally small.

     

    Regional Breakdown

     

    Difference from the average (1971-2000)

    Mean Max

    (deg C)

    Mean Min

    (deg C)

    Rainfall

    (per cent)

    Sunshine

    (per cent)

     

     

     

     

     

    Scotland (Highlands and Islands)

    –0.3

    –0.2

    79

    132

     

     

     

     

     

    Scotland - Central Belt and east coast

    –0.7

    –0.4

    81

    122

     

     

     

     

     

    Northeast England

    0.0

    +0.1

    66

    128

     

     

     

     

     

    East Anglia

    +0.3

    +0.8

    103

    92

     

     

     

     

     

    Midlands

    +0.1

    +0.3

    79

    99

     

     

     

     

     

    Southeast England

    0.0

    +0.9

    125

    83

     

     

     

     

     

    Northwest England and North Wales

    –0.5

    –0.8

    75

    105

     

     

     

     

     

    Southwest England and South Wales

    –0.6

    –0.5

    99

    100

     

     

     

     

     

    Northern Ireland

    –1.1

    –0.7

    53

    159

     

     

     

     

     

    IrishRepublic

    –1.4

    –0.8

    57

    139

     

     

     

     

     

     

    © Philip Eden 110131