Mild again!

With a maximum temperature of 8.2C (+1.2C) and minimum of 4.7c (+3.6C) Saturday was another mild day and night. A little rain fell overnight amounting to just 0.9mm.

Sadly Sunday saw another start to a day with total cloud cover although winds are light and from the south west.

Hopefully the Daily Stats section will be up and running in a day or two.

A Meteorological Review of 2019

January is a winter month and we certainly had wintery weather with snow and fog. The month began with sub-zero temperatures on four successive nights with a minimum of -5.8C during the early hours of the 5th, which was 7C below the 34-year average. Unlike the autumn months it was very dry with 14 successive rainless days from the 1st to the 14th. There followed modest rainfall days totalling 43.3mm, which was less than half the long-term average. However, this total included precipitation from the snow that fell on three days toward the end of the month that lasted for 22 hours into the start February. This was the driest January since 2006.

February started with another period of extreme cold as the thermometer did not rise above 0.5C on the 1st due to the copious snow cover and later plummeted to -11.3C on the 4th being 12.6C below the 34-year average. Contrasting that cold was the record warmth at the end of the month. A maximum of 18.2C was logged on the 26th, which was 11.1C above average and broke the previous record set in 1998. Rainfall of 65.3mm was almost exactly average although there were 16 totally dry days.

The first month of meteorological spring, March was very simply a month of two halves as rain fell every day from the first to the 18th followed by 13 dry days. The rainfall total was 69.8mm being 10.3mm above the 35-year average. The wettest day occurred on the 5th with a total 13.8mm. There was a turbulent period in the middle of the month when the westerly winds reached 40mph and 47mph on the 14th and 16th respectively. The one occasion that hail was noted in 2019 occurred on the 10th.

April was a predominantly dry month with only two rain days between the 10th and the month’s end that meant that only 74% of the average rainfall fell in Marlborough. The wet day on the 4th produced 18.8m of the month’s total of 43mm. There was a very warm period in the third week with six days recording maxima in excess of 20C and peaking at 23.9C on the 22nd when the average was 14C.

May was a relatively cool month for late spring with the mean just below average. But it was another month with very many dry days, 21 in fact that belies the fact that out of the rainfall total of 59.5mm, 17.8mm and 18.9mm fell during the very wet days on the 8th and 9th. At the end of the month temperatures began to rise with a minimum of 13.9C on the well above average (+6.8C). With sunshine recorder now back from repair it logged 12.4 hours of sunshine on the 14th.

The first month of meteorological summer, June was a disappointing summer month, wetter than average and below average solar energy, all due to a depression that was reluctant to depart our shores as it slowly revolved anticlockwise around the UK for many days bringing cloudy conditions. The first two days were very warm; peaking at 25.6C on the 1st, but thereafter went downhill with 18 consecutive days of below average maxima, as were the minima. With only 13 dry days it was a predominantly wet and cloudy month with considerable rainfall, the total of 70.7mm was 17mm above the 35-year average with a very wet day on the 10th producing 25.1mm. The UV level for this summer month was lowest since 2012.

July was another month of simply two halves. During the first 16 days of the month we had just 0.3mm of rainfall, which fell on the 6th with the remaining 15 days totally dry. However, with the wind then backing predominantly into the southwest the rains arrived, especially on three particular days. The daily rainfall on the 19th, 23rd and 30th was 12.9mm, 12.2 mm and 15.3mm respectively. These three days accounted for 67% of the monthly total, which at 50.8mm was 9.1mm below the 35-year average. The latter half of the month was hot with several days when the peak temperatures were well above average. Examples were 32.0C on the 23rd and 32.6C on the 25th, the latter being almost 10C above average. Not surprisingly the mean temperature was 1.2C above the 35-year average.

We then come to August, the last month of summer meteorologically. From the 4th the rains set in with very wet days on the 8th and 14th that logged 14.6mm and 10.4mm but this paled into insignificance with a deluge of 28.1mm on the 16th. The rainfall total of 81.6mm was 124% of the long-term average however there were several dry and very warm days to end the month with the hottest on the 25th with a maximum of 30.7C that meant the mean for the month was 0.8C above average.

The beginning of meteorological autumn, September, was been a month of extremes. The first 20 days saw little rain, just 7.3mm, with ten totally dry days. Thereafter every day was wet with considerable rainfall. The heaviest rainfall occurred on the 23rd with a total of 29.6mm, the days on either side each producing thunder on two occasions. The rainfall for the month amounted to 111.4mm. This was 181% of the 35-year average or plus 50mm also the wettest September since 2006 when a record 131.9mm fell. The contrasting year was in 2009 when as little 11.1mm was recorded. The other significant daily totals were 18.6mm, 23.0mm and 10.0m on the 24th, 28th and 30th respectively. It was an average month temperatures wise with the thermometer peaking at 24.9C on the 21st. During the month 168 hours of sunshine were recorded with many days in the middle of the month seeing almost wall-to-wall sunshine with 10.25 hours of sunshine being recorded in the 13th.

October began under the threat of Hurricane Lorenzo that formed in Mid-Atlantic approaching from the west. This was the strongest hurricane to have been recorded so far east in the Atlantic. It produced waves as high as an eight-storey building around the Azores. Fortunately for this country Lorenzo had been downgraded to a storm by the time it crossed our shores. However, Lorenzo did bring winds gusting to 31 mph, combined with moderate rainfall amounting to 8.4mm on the October 1st. This set the pattern for the remainder of the month as the powerful jet stream, running in excess of 150mph, produced a conveyer belt of depressions arriving from the Atlantic. There was an exceptionally wet and windy period around the second week in the month. Several days produced rainfall in double digits, 15.1mm, 28.7mm and 15.4mm on the 11th, 13th and 14th respectively. The monthly rainfall average of 83.6mm was overtaken by the time we reached the 13th and continued to be added to throughout most of the month, producing a monthly total of 153.1mm, which was 183% of the 35-year average or 69.5mm above. There were just 8 dry days in October. It is not surprising that this was well below the average of 14 with so many depressions crossing the country. Due to the many cloudy, gloomy days the temperatures were depressed producing a mean of 9.7C, which was 0.8C below the 35-year average.

November began much as October with an ex-hurricane affecting our weather. Pablo was the first such storm to form so close to the UK, just west of Iberia. It brought mild weather with a peak of 14.5C on the 1st. The warm air was maintained during the nights also but high winds with a gust of 38mph on the 2nd. There were just 7 dry days in November. It is not surprising that this was well below the average of 14 with so many depressions crossing the country. Due to the many cloudy, gloomy days the temperatures were also depressed producing a mean of 9.7C, which was 0.8C below the 35-year average. Once again we have been very fortunate in that the torrential downpours were away from this part of the country. Whilst we had very wet days the Peak District, for example, had 112mm in 24 hours. Following this period the weather took a turn for the worse with both maxima and minima below average. There were 19 consecutive days with below average daytime peaks, with just 4.6C on the 30th being the coldest in November, a drop of 5.5C on the average. The jet stream subtly changed direction mid-month allowing the barometric pressure to rise to its highest reading all month at that time of 1018.1mb on th18th. This gave a slightly drier period with five dry days between 16th and 20th, just 0.3mm on the 17th. The rainfall for the month amounted to 116.7mm, which was 24.6mm above the 35-year average. So in summary a cool, wet and predominately gloomy month with no UV registered during 5 days and 10 when the sunshine recorder was not triggered.

The start of December was in direct contrast to the two previous months, as it did not start with heavy rain and strong winds. Polar Air brought dry and cold air. By the 4th we had enjoyed four consecutive dry days, the first since the middle of September, with maxima of only 5.5C and 5.4C. However, by the 5th normal unsettled weather returned as another procession of depressions crossed the country with considerable rainfall and strong winds. With frequent depressions approaching and crossing the UK it was sometimes difficult to detect the prominent wind direction for each 24-hour period as the wind was constantly changing direction. There were several days when the wind changed up to 180 degrees in a matter of a few hours. Notable daily rainfall totals were 20.2mm, 13.9mm and 15.9mm on the 12th, 18th and 19th respectively. The rains continued throughout most of December after the 9th with 18 continuous days when varying amounts of rain were recorded from the 10th to the 27th. On the 19th a depression in the eastern Atlantic, rotating anticlockwise as they do, brought warm air from Iberia with the thermometer rising to a maximum of 10.7 and 10.8 on the 18th and 19th respectively. After so may wet and gloomy days in the month it was such a relief to enjoy 5.2 hours of glorious sunshine on Christmas Day. The month did finish on a drier note with 4 consecutive dry days; however there were only 8 dry days in the month when the average is 13. The mean temperature for December was 0.8C above the 35-year average due to the frequent cloudy nights minimising any frost occurring, just 6 occasions, with the lowest recorded on 5th when the thermometer fell to -3.4C. The total rainfall for December amounted to 130.5mm, which was 39.8mm above the 35-year average and the wettest since the record of 157.0mm in December 2013. It was the 7th wettest December since my records began in 1984.

Further 2019 Statistics for my station that opened in 1984

UV level: the maximum exposure reading of 9.7 on 1st July placed this at the top end of ‘very high’. There were 27 days when no UV light triggered the instrument, 14 of these days occurred in December

Evapotranspiration: the loss of moisture into the atmosphere from ground sources and plant life was at its maximum on 23rd July with the equivalent loss of rainfall of 5.04mm during that day.

Temperature: The hottest day occurred on the 25th July with a peak temperature of 32.6C. Not a record as 34.9C occurred in July 2006
The coldest night, often occurring early morning, was recorded on 3rd & 4th February with a minimum of -11.3C. Not a record as -13.5C occurred in December 1999.
The mean annual temperature was 10.3C. The extreme years were in 1986 with a mean of 8.0C and 2011with 10.7C
The Diurnal temperature range is the variation of temperature between the maximum and minimum on anyone day. Whilst the range for the months from April to October show minimal variation, the same is not true for the winter and early spring months that show a widening trend. For instance the variation for November that in the 1980s gave a maximum variation of approximately 11C now have increased to almost 14C. The remaining winter early spring months indicate an increase in the order of between 2C and 3C.

Air Frosts: An air frost occurred during 49 nights. Not a record as 98 air frosts were recorded in 2010.

Wind: The maximum wind speed was a gust of 47mph measured on 15th March. Not a record as on two occasions, January and March 2007, 57mph was noted.
The predominant wind direction was from the southwest on 80 days followed by 67 days from the south.

Rainfall: The total rainfall for 2019 was 995mm. This was not a record as 1146mm fell in 2002. The driest year was 1996 with 594mm.
The wettest month was October with 153.1mm and the driest in April with 43mm.
On 23rd September 29.6mm of precipitation was recorded making this the wettest day in 2019. Precipitation of course means rain, hail, sleet, ice pellets, snow etc.
There were 184 Rain Days, classed as precipitation => 0.2mm and 139 Wet Days classed as precipitation =>1mm.

Barometric Pressure: For much of the year the Jet Stream, producing a conveyer belt of depressions, meant that the pressure was frequently rising high then shorty afterwards falling away again. The highest pressure of 1044.6mb was recorded on 3rd January whilst by contrast the lowest pressure of 969.6mb occurred on 6th December

Snow: fell on 4 days

Thunder: was noted on 4 days