The averaging period used for the following assessment was 1961-1990.
Very warm and sunny across all parts of the UK. Rainfall was well below or exceptionally below average across the majority of the UK.
Highest temperature was 38.5 °C at Brogdale near Faversham (Kent) on 10th, breaking the UK temperature record. Greycrook (Scottish Borders) beat the Scottish temperature record, when 32.9 °C was reported on the 9th. Carlton in Cleveland reported 48 mm of rainfall in just 15 minutes on 10th.
England and Wales diary of highlights
Very warm and dry overall. Record breaking heatwave second week.
1st to 2nd Low pressure to the north-west brought a breezy start to the month with occasional rain and drizzle, however it became sunny and warm by the 2nd.
3rd to 13th A notable and record breaking heatwave especially in the midlands, central southern and south-east England and East Anglia as high pressure took control bringing prolonged sunshine to most areas. Temperatures topped 30 °C somewhere for 10 days in a row and exceeded 35 °C in many places on the 6th, 9th and 10th. There was some patchy hill and coastal fog mainly around south-west and western areas. The 5th and 6th saw a little thunder in the north, while rain affected the north-west on the 9th. Valley (Anglesey) reached 33.0 °C on the 5th, with 35.0 °C recorded at Rocquaine on Jersey, both new station records. The 9th and 10th saw extreme heat across much of the region, particularly in south-east England on the 10th where 38.5 °C was recorded at Brogdale near Faversham (Kent), a new UK temperature record. Most stations in Greater London reported around 38 °C breaking their previous highest. In contrast there were thunderstorms in north, west and central areas of the region, with severe outbreaks over north-east England. Carlton in Cleveland (North Yorks) collected 48 mm in 15 minutes with 2 cm of hail on the ground and Middlesborough had 30 mm in a downpour. There was more thunder in west, north-west and north-east areas on the 11th. It continued mostly hot with a little thunder in the south-west on the 13th as a cold front moved south-east.
14th to 18th Changeable with occasional rain or showers in places, mainly in western and southern areas and cooler, though still warm or very warm at times. There were good sunny periods generally, especially inland and in eastern areas. Developing low pressure to the north brought fresher air from the north-west during the 18th.
19th to 26th Dry and mostly warm with sunny periods at first but more breezy in the north on the 21st as a low tracked eastwards passing by north Scotland. Slow moving fronts gave light rain and drizzle in many places during the 21st and 22nd and in the north-east on the 23rd. High pressure then re-established itself over the UK but retreated to Iceland by the 25th allowing cooler cloudier conditions and a little rain and drizzle to spread in from the north-east.
27th to 31st An anticyclone near Iceland and low pressure over Scandinavia fed markedly cooler air from the Arctic. The cold front stalled over southern districts on the 28th as a depression from Biscay moved east-north-east bringing much needed rain to these areas. This rain, heavy at times with some thunder, moved away during the 29th. Mainly dry weather followed, with sunny periods; northern districts experienced scattered showers and ground frost.
Scotland diary of highlights
Dry and sunny with a memorable heatwave.
Anticyclonic conditions dominated August, with unsettled conditions limited to the period from the 17th to the 22nd. A memorable heatwave was experienced from the 5th to the 9th, although it was much cooler by the end of the month.
South-westerly winds covered Scotland for the first few days, bringing sunny intervals, with showers dying out as pressure rose.
From the 5th to the 9th a large area of high pressure covered the British Isles or the North Sea. Dry and sunny weather prevailed and the temperature reached or exceeded 29 °C somewhere in Scotland every day. The highest temperature was 32.9 °C at Greycrook (Scottish Borders) on the 9th, just beating the previous Scottish temperature record of 32.8 °C. On the 7th the summit of the Cairnwell recorded 25 °C, and many stations observed their highest ever temperature during this spell. Some west coast stations recorded minima of 19 °C on the 6th and the 9th.
A cold front crossed Scotland overnight between the 9th and 10th, and although anticyclonic conditions were renewed, it was much cooler than before. Another cold front passed over between the 12th and 13th, with high pressure rebuilding to the west and then advancing over Scotland. Dry and sunny weather returned to most parts, with pleasantly warm days. However, it was much colder at night with the temperature falling to 1 °C at Tulloch Bridge on the 16th.
From the 17th to the 22nd low pressure near Iceland directed a westerly airflow across Scotland, with humid air and a succession of fronts. It was mostly cloudy and breezy with rain at times, mostly in the west.
Another anticyclone formed over Scotland on the 23rd and 24th and then moved towards Iceland. There was more sunny weather with cool nights and warm days at first, with cloud spreading to the east on the 25th and 26th as winds turned into the north-east.
During the last five days a cool north-northeasterly airstream covered Scotland. There was much bright weather but also showers, mostly in the northeast, that gradually died out. The temperature fell to 1 °C at Biggar on the 30th and 31st.
Northern Ireland diary of highlights
Warm, dry and sunny.
August 2003 was a very pleasant summer month, with above average temperatures and sunshine and with rainfall well below average. There were no wet or dull spells of weather during the month, and daytime maximum temperatures were persistently high across all areas between the 3rd and 12th. Cooler conditions were experienced during the last week however, and this reduced monthly mean temperature values across all areas. Notably severe thunderstorms affected all areas of Northern Ireland on the 5th, although rainfall totals were mostly not significant. The wettest day of the month generally was the 17th when all areas received some rainfall, and locally up to 10 mm were recorded.
1st to 4th Predominantly dry and warm with variable sunshine. Became very warm by the 4th.
5th Very warm or hot with severe thunderstorms breaking out and spreading northwards across all areas during the day.
6th to 16th Largely dry, very warm and locally hot on some days, and very sunny.
17th to 27th Quite wet in some areas on the 17th, otherwise generally small amounts of rain on some days. Continuing warm with temperatures around 2 °C above normal for the time of year, but much less sunny than during the first half of the month.
28th to 31st Cool but with only isolated light showers and with variable amounts of sunshine.