The second half of June and early July were generally unsettled, with a deep June depression passing over England on 23 June 2004.

Another depression coming up from Spain/France, caused high wind speeds and heavy rainfall on 7/8 July 2004. This was followed by heavy showers/thunderstorms over parts of England on 8 July 2004.

Six-hourly animated synoptic charts

This unseasonably bad weather resulted in problems for power supplies, on roads and on the railways. There were also flooding problems near Wittering on 8 July 2004, which recorded over 100 mm in just 18 hours, which is double their July 1961-90 average, though much higher amounts have been recorded over the UK over much shorter durations.

United Kingdom extreme weather

The table and map below uses wind data available on 9 July 2004 (only stations with small amounts of missing wind data over the two days have been used, and no adjustments have been made for stations which do not have a standard effective height of 10 metres). Data are provisional, and have not yet been fully quality controlled.

Map of highest hourly mean wind speeds - 7 and 8 July 2004

Highest gust speeds - 7 and 8 July 2004

The table and map below uses wind data available on 9 July 2004 (no adjustments have been made for stations which do not have a standard effective height of 10 metres). Data are provisional, and have not yet been fully quality controlled.

The highest known gust speed any where in UK during July is 81 knots (93 m.p.h.) at Lizard on 29 July 1956.

Map of highest gust speeds - 7 and 8 July 2004

Rainfall information - 7 July 2004

The following table, consists of the data which were available from our real-time network on 8 July 2004, and shows the highest rainfall totals for various periods on 7 July 2004. Data are provisional, and have not yet been fully quality controlled.

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please Note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Rainfall information - 8 July 2004

The following table, consists of the data which were available from our real-time network on 9 July 2004, and shows the highest rainfall totals for various periods on 7 July 2004. Data are provisional, and have not yet been fully quality controlled.

Twelve-hour standard period is defined as 09-21 GMT or 21-09 GMT.

Please Note: The return periods have been calculated using the Flood Estimation Handbook method. This gives the likelihood of recurrence at any time of year, rather than for the month in question only. Return periods less than 10 years have been noted as insignificant in the above table.

Extra information on Wittering

Wittering recorded 107.4 mm in 19 hours on 7/8 July 2004, which is an approximate return period of 150 years. This volume of rain has not been previously recorded over such a short time frame at Wittering for any month.

Over the first 8 days of July, Wittering recorded 121.5 mm, which is 246% of their 1961-1990 July average rainfall.

A short account from the Senior Met. Officer at Wittering, which gives further insight into the event.

"The thunderstorm on Thursday afternoon was very localised indeed. I suspect only a few square miles were affected, the area centred on RAF Wittering. The A1 road is adjacent to our entrance and was closed for a while.

"The whole base was flooded with several buildings affected. Ground stroke lightning was also a feature with several "hits" on the base resulting in damage to electronic equipment.

"The thunderstorm was not advected from elsewhere but appeared to develop over Wittering in a short space of time and then hardly move. Some hail was observed but nothing too intense. The rain was just like standing under a waterfall."