April 2013 continued the wintry theme without any early sign of spring, initially. For the first seven days maxima were in single figures with sharp overnight air frosts and a minimum of -5.1C on the 7th. As the persistent northeasterly winds gave way to those from a more southerly direction, temperatures by day and night began to recover. The increased cloud cover brought substantial rainfall amounts from 10th to 13th with a maximum of 14.6mm on the 10th.
Not surprisingly, the mean temperature was 1.1C below the long-term average with a maximum of 18.9C on the 23rd. It was the fifth coldest April over the last thirty years and reminiscent of mean monthly figures for the late 1980’s. Air frost occurred on 10 nights, the highest number since 1997, when the average is just 6 occurrences in April.
The rainfall total of 48.6mm was 80% of the long-term average. It is interesting to note that the total for 2012, of 145.8mm, was three times the quantity recorded in 2013 and in direct contrast to just 5.4mm in 2011.
Snow flurries were seen on the 4th and hail on the 26th and 27th. Fog occurred on two mornings and early mist on two other occasions.
An unusually raised level of UV radiation was recorded on three days, namely 22nd, 23rd and 25th. The usual level for April is classed as ‘moderate’ but the peak recorded figures were rated as ‘high’ that mostly occur on a few days in May.
