UK Review - July 2009

The heatwave that began in late June lasted for the first few days of July, with temperatures widely approaching 30C at first.

It was provisionally the wettest July in England and Wales on record. Sunshine and temperature amounts were close to the seasonal average.

The high temperatures soon became confined to eastern areas, as thundery downpours broke out elsewhere causing some localised flooding and disruption to transport.

From the 5th onwards, the weather was generally very unsettled with often thundery showers and longer periods of rain. These were also often accompanied by localised flooding.

On the 7th some of the worst downpours affected south-east England, with around 90mm of rainfall reported from the Hastings area in Sussex. A number of Tube stations in London were flooded during the evening and a Royal Garden Party at Buckingham Palace had to be abandoned.

On 16th and 17th, rainfall was widespread. Wales and south-west England were most affected on 16th with roads in Cornwall closed due to flooding and a landslip on the A38 near Bodmin.

94mm of rainfall was recorded on 16th at nearby Cardinham. By 17th, the focus of the persistent heavy rain had moved to north-east England and the Scottish Borders. Rainfall totals approached 100mm in places, with 116mm at Alston, Cumbria in the 48 hours from 16th to 17th.

The greatest impact was seen seen over north-east England with a number of properties flooded, disruption to road and rail transport and interruptions to power supplies.

July continued with a very unsettled theme, with many examples of travel delays and disruption to outdoor events.

A small tornado was reported to have damaged a number of homes and cars in Stornoway on the Isle of Lewis on 28th. Over 100 children were evacuated from a lakeside campsite at Keswick due to flooding on the same evening.

Heavy rain also caused the cancellation of the Brecon Agricultural Show in mid-Wales as well as delaying the start of the third Ashes Test at Edgbaston, Birmingham on 30th.

Statistics

Mean temperatures were close to the 1971-2000 average across the UK. The largest departure from this was 0.8C above normal over Scotland, whereas Wales and parts of western England were slightly below normal.

The month was similar to July 2008, but somewhat warmer than July 2007.

Rainfall was significantly above the seasonal average in almost all areas, particularly in a broad swathe stretching from south-west England through Wales, the Midlands, northern England and into eastern Scotland.

These areas recorded over twice the average July rainfall, with south-west England, south Wales and parts of north-east England recording over three times the seasonal average amount.

The drier areas were in northern and western Scotland and eastern East Anglia, with up to 150% of the July average.

Provisionally, it was the wettest July on record over England and Wales (in a series from 1914), being slightly wetter than July 2007 and much wetter than July 2008.

Over Wales it was ranked 2nd in this series, with only July 1939 being wetter.

Over the UK, it was also wetter than July 2007 and 2008 and provisionally ranks 4th but close to the July totals in 1936, 1939 and 1988.

Sunshine was close to the 1971-2000 average across the UK, with northern and western Scotland faring best with about 120% of the seasonal average. The wettest areas were also the dullest, with south-west England and Wales recording typically 80% of the average sunshine.

A maximum temperature of 30.9C was recorded at Heathrow (Greater London) on the 1st.

Tulloch Bridge (Highland) recorded a minimum temperature of 1.0C on the 10th.

Cardinham (Cornwall) recorded 94mm of rainfall in the twenty-four hours ending at 0900 on the 17th.