British Extremes

HailstormArtist's impression of the Wellesbourne hailstorm
(Credit: Chris Chatfield)

Earliest severe (≥H3) hailstorm

The earliest known severe hailstorm in Britain occurred at Wellesbourne in Warwickshire in May 1141 and was at least H3 in intensity on the TORRO Hail Scale. However, there are believed to have been one or more fatalities caused by hail - which would infer very large stones and hence a much higher intensity rating.

No equivalent data is currently available for the continent.

Longest-track hailstorm

On 22 September 1935, an H6 hailstorm tracked 335 km from the west-south-west from Newport (Gwent) to Mundesley (Norfolk). It is likely that the true length was longer still, as the storm probably tracked along the Bristol Channel for some distance before reaching Newport, as well as continuing over the North Sea after Mundesley.

No equivalent data is currently available for the continent.

HailstormArtist's impression of the Hitchin to Great Offley hailstorm (Credit: Chris Chatfield)

Most intense hailstorm

Several hailstorms have reached H7 in Britain, but only one H8 has been recorded. On 15 May 15 1697, an H8 hailstorm tracked from Hitchin north-eastwards to Potton (Bedfordshire), a storm swathe at least 25 km long. At Offley, near Hitchin in Hertfordshire, the hailstones were measured at 343 mm circumference with some anecdotal reports indicating 445 mm. These correspond to measurements of about 110 and 140 mm diameter, respectively, and the pieces of ice were described as 'some oval, some round, some flat'. The ground was torn up, and great oak trees were split. Tiles and windows of houses were all shattered to pieces. At least one human fatality was attributed to the hail, a young shepherd.

No equivalent data is currently available for the continent.

Heaviest hailstone

The heaviest hailstone officially recorded in Britain fell from the H7 storm which tracked 150 km from West Wittering (West Sussex) to Maldon (Essex) on 5 September 1958 - the stone, which fell on Horsham (Sussex), weighed 190 g. However, descriptions from older accounts which do not usually quote weights clearly indicate that significantly heavier stones have fallen in Britain (even when suspected exaggeration is taken in to account). In the great Somerset hailstorm of 15 July 1808, many were reported as weighing over 220 g.

No equivalent data is currently available for the continent.

Webb, J. D. C, Elsom, D. M, and Reynolds, D. J (2001) Climatology of severe hailstorms in Great Britain, Atmospheric Research 56, pp 291-308

Webb, J.D.C., Elsom, D.M., Meaden, G.T. (2009) Severe hailstorms in Britain and Ireland, a climatological survey and hazard assessment. Atmospheric Research, 93, 587–616.

Webb, J.D.C., Elsom, D.M. Severe hailstorms in the United Kingdom and Ireland: a climatological survey with recent and historical case studies. In: Extreme Weather. Forty years of the Tornado and Storm Research Organisation (TORRO), 1st Edition. Wiley-Blackwell and John Wiley and Sons: Chichester, UK (Chapter 9).