Hail, thunder then air frost – is it Spring?

Thursday started off bright and dry but the shower activity increased as the air temperature eased upwards with three hail showers starting at 14.30 then 14.35 and 14.55. The total precipitation was 2.7mm with a clap of thunder at 14.34. Before these events the thermometer had reached 12.3C being 5C below average in the brisk west-northwest breeze. Over the course of half an hour, as the hail and rain descended, the thermometer dropped over 5C from 11.5C to 5.9C.

Clearing skies overnight meant the shower activity diminished, which led to an air frost lasting over three hours with a minimum of -0.9C, which was 7.8C below the 37-year May average.

Initially on Thursday there was a little brightness. However, a trough of low pressure over the area, between two depressions, produced a bank of thick cloud that arrived from the north west, which limited the temperature recovery with a reading of only 2.1C at 08.00. The soil temperature over the past few days had lifted a little to around 7C or 8C but this morning, after the hail and frost, read just 4.8C at a depth of 5cm.