2003 European heat wave
Canicule Europe 2003.jpgLow water level in Haweswater Reservoir, September 2003

The United Kingdom experienced one of its hottest summers on record with temperatures well above average. However, Atlantic cyclones brought cool and wet weather for a short while at the end of July and beginning of August before the temperatures started to increase substantially from 3 August onwards. Several weather records were broken in the United Kingdom, including a new record for the country's highest ever recorded temperature of 38.5 °C (101.3 °F) at Faversham in Kent on 10 August, which remained the highest recorded temperature in the UK until the heatwave in July 2019. This was the first occasion on which temperatures exceeding 100 °F (38 °C) have ever been officially recorded in the UK.[28] Scotland also broke its highest temperature record with 32.9 °C (91.2 °F) recorded in Greycrook in the Scottish borders on 9 August.

Due to a number of deaths, the UK government released its Heat Health Watch system, issuing warnings if temperatures rise above 30 °C in the day and 15 °C at night.[29] According to the BBC, over 2,000 people more than usual may have died in the United Kingdom during the 2003 heatwave.[30]

The tarmac melted on part of the M25 between Junctions 26 and 27,[31] and rails buckled from expansion on the hottest day in England in 13 years, while 2 teenaged boys drowned while trying to escape the excessive heat.[32]


The summer of 2003 was warmer than average in Ireland, but the heat was far less pronounced there than in the rest of Europe. August was by far the warmest, sunniest, and driest month, with temperatures roughly 2 °C above average. The highest temperature recorded was 30.3 °C (86.5 °F) at Belderrig, County Mayo on 8 August.[33][34][35]


Remarkably, Scandinavia saw a cooler August in 2003 than the previous year when comparative temperatures were very high for the latitude, as the hot air parked over continental Europe. Only the deep southern Sweden saw any type of heatwave effect in the country, with the average high of Lund for August being 23.9 °C (75.0 °F), which is a very warm temperature average for August.[36] In spite of this the Scania County stayed below extremes of 30 °C (86 °F) indicating a more subtle kind of heat. The records from 1997 and 2002 held up all throughout the country, and the warmest temperature was 30.8 °C (87.4 °F) in Stockholm on 1 August, which was higher than the warmest Irish temperature. Although a comparatively low exposure to the heatwave this is to be expected given the greater continental influence. When compared with the 1961–1990 averages the 2003 August month was still a couple of degrees warmer than a normal August in the southern third of the country.

The bulk of the heat wave in Sweden was instead seen earlier in July in the central and northerly parts of the country, where Stockholm had a July mean of 20.2 °C (68.4 °F) with a high of 25.4 °C (77.7 °F) which although very warm was not record-setting.[37] The warmest summer temperature was set on 17 July in the northern city of Piteå with 32.8 °C (91.0 °F), which although it is very hot for such a northerly coastal location, was largely unrelated to the latter central European intense heat wave. In northern Sweden, August temperatures are rarely warm due to the decreased exposure of the low but everlasting sun during the summer solstice. As a result, temperatures there peak in July if it is a warm summer.

Effects on crops

Crops in Southern Europe suffered the most from drought.


These shortfalls in wheat harvest occurred as a result of the long drought.[citation needed]

  • France – 20%
  • Italy – 13%
  • United Kingdom – 12%
  • Ukraine – 75% (unknown if affected by heatwave or an early freeze that year)
  • Moldova – 80%

Many other countries had shortfalls of 5–10%, and the EU total production was down by 10 million tonnes, or 10%.[citation needed]


The heatwave greatly accelerated the ripening of grapes; also, the heat dehydrated the grapes, making for more concentrated juice. By mid-August, the grapes in certain vineyards had already reached their optimal sugar content, possibly resulting in 12.0°–12.5° wines (see alcoholic degree). Because of that, and also of the impending change to rainy weather, the harvest was started much earlier than usual (e.g. in mid-August for areas that are normally harvested in September).

The wines from 2003, although in scarce quantity, are predicted to have exceptional quality, especially in France. The heatwave made Hungary fare extremely well in the Vinalies 2003 International wine contest: a total of nine gold and nine silver medals were awarded to Hungarian winemakers.[38]

Effects on the sea

The anomalous overheating affecting the atmosphere also created anomalies on sea surface stratification in the Mediterranean Sea and on the surface currents, as well. A seasonal current of the central Mediterranean Sea, the Atlantic Ionian Stream (AIS), was affected by the warm temperatures, resulting in modifications in its path and intensity. The AIS is important for the reproduction biology of important pelagic commercial fish species, so the heatwave may have influenced indirectly the stocks of these species.[39]

See also