After the arctic blast on Wednesday, both day and night, the slight shift in wind direction from north to northwest meant a slightly warmer day yesterday with a maximum of 10.6C, but this was still 3C below the average. Sadly, the intense and lengthy cold meant my rhododendrons and apple blossom were very badly affected. There was a little sunshine between the heavy clouds and a couple of light showers amounting to 0.6mm, which brings the total to 6.1mm for April, the third driest I have recorded since 1984 when the thirty-three year average is 59.7mm. Overnight the cloud cover meant that the thermometer did not drop below 4.8C. This morning broke with continuous cloud cover that has the promise of breaking as the day progresses with the thermometer recovering to 7.0C at 08.00. It has been a month when only two days have not registered strong sunshine, if minimal, with a total of 148 hours to date.
Wednesday was even colder than the previous day with a maximum of 9.7C, the coldest day this month, but the wind chill factor reduced this by 2C. Late afternoon another rain shower gave us 1.2mm of rain bringing the total for April to 5.5mm. At this time the thermometer started to drop and continued falling almost continuously until this morning. The minimum temperature was -3.0C, the coldest April night since 2013, that occurred at 05.45 with the thermometer rising to 2.0C at 08.00 under the influence of a strengthening sun. There were eight hours of sub-zero temperatures. The soil temperature at a depth of 5cm was reading 3.4C at 0800, the lowest for a month.
What a day of contrasts yesterday was? The brisk northerly wind pegged back the daytime temperature to a maximum of only 9.8C, some 4C below the average and the coldest day since 6th March. Out of the wind the 5.92 hours of sunshine were quite strong with a UV level at the top end of ‘Moderate’. However, at 19.15 a storm arrived with initially large rain drops that by 19.24 turned to wet snow and lasted for over ten minutes. There was not a great quantity of precipitation, just 2.2mm, but it was the wettest day this month and brings the total for April to 4.4mm, the second driest April since my records began in 1984. At this time thermometer dropped over 4C to a low of 1.8C and the wind gusted to 29mph, the strongest gust for over a month.
Overnight the thermometer dropped to a low of 0.6C giving a ground frost but not an air frost. At daybreak everywhere was white due to the precipitation last night unlike the previous night when there was an air frost but not noticeable due the every dry air at that time.
This morning has dawned with thick cloud and only the briefest glimpses of sunshine and a temperature that has recovered to 3.7C at 08.00
Monday gave us some brief sunshine in the early morning, before the cold front brought thick cloud and obscured the sun, amounting to just 10 minutes. The influence of the initially westerly breeze and lack of sunshine meant a day with below average temperatures with a maximum of just 12.9C at 13.47 (1C below average). Just after 5pm the cloud thickened, the wind veered into the north and the thermometer began to fall steadily in the cooler air. This made yesterday the wettest day this month with just 1.1mm, bringing the total for April to 2.1mm making it the second driest April since my records began in 1984. Yesterday is classed as a wet day, which meteorologically is any twenty-four hour period with precipitation equal to or exceeding 1mm.
To sum up yesterday: lowest night temperature, lowest solar, lowest evaporation, strongest wind gust and wettest day.
There was an air frost for a couple of hours starting just after 3am this morning, giving a minimum of -0.7C. There was little evidence of this due to the very dry air, 81% humidity at 08.00.
Sunday gave us a very sunny morning with 5.28 hours in total, which became intermittent in the afternoon. However, with light breezes, maximum gust of 12mph, the thermometer rose to a high of 15.4C, still above average for April. Overnight the temperature fell steadily until a minimum of 2.9C was reached at 06.30.
At dawn there was quite thick valley fog with visibility down to 300m. However as the sun got to work it slowly began to lift but the leading edge of the much heralded cold front could be seen advancing from the north west and by 07.30 it had totally obliterated the glorious early morning sunshine.