Topsy turvy weather. Cool, warm and back to cool. April review.

Wednesday was a cool day with the thermometer reaching a maximum of 15.6C, which was 1.5C below the early May average. The wind, then veering into the west, brought the cooler and moister air mass.

There were a couple of very light showers in the afternoon amounting to just 0.4mm.

The minimum overnight was also below average (-1.5C) with a low of 5.6C

Thursday saw broken sunshine early morning but cloud beginning to build after 08.00 when the thermometer had recovered to 9.1C

April 2019 Review

The beginning of April looked as if we were in for a wet month with several wet days and a deluge on the 4th that produced 18.8mm. However, after the 9th it was a predominantly dry period, just two wet days.

The April rainfall amounted to 43.0mm, which was 15.3mm below the 35-year average. Although a relatively dry month this pales in comparison with the minuscule amount of 2mm that fell in the whole of April 1984. The opposite was true of 2000 when we were almost submerged under 165.2mm of rainfall, which was almost three times the April average.

Analysing the rainfall for the first four months of 2019, I find that the total is 221mm being 54mm below the 35-year average for this four-month period.

We must also take into account that evaporation into the atmosphere, from ground sources and plant life, amounted to the equivalent rainfall of 71mm thus producing a deficit over the month of 28mm.

Turning to the April temperature data I find that the average was 0.6C above the 35-year average, principally due to very cool Aprils in the late 1980’s and early 1990’s. However, comparing 2019 against the last 10 years it was average.

There was a warm period from the 17th to the 24th that saw six days when the thermometer rose above 20C when the average is 14C. The warmest day occurred on the 22nd with a maximum of 23.9C. Early April was decidedly cool with a maximum of just 7.7C on the 3rd followed by an even cooler day on the 4th when the thermometer refused to climb above 5.4C set against the daytime average of 14C.

An air frost occurred during the early hours of five mornings with the lowest temperature set on the 3rd with a minimum of -3.2C.

Regrettably my sunshine recorder had to be moved from its rooftop position for expert attention as it developed a fault but there were many days of strong sunshine with peak solar energy recorded on the 21st and the UV level rising into the ‘high’ category on five days during the last week.

There many days with little wind but the period from the 24th to the 27th was particularly windy with wind speed maximum gusts of 22mph, 26mph, 31mph and 42mph respectively as Storm Hannah approached and then traversed the country.

Fog occurred at dawn on three days with visibility down to 100m on the 17th.