Parts of Europe, the Middle East, North Africa and southwestern USA have seen extremely high May and June temperatures, with a number of records broken. The heatwaves in Europe, which started unusually early, is now forecast to move eastwards to the eastern Mediterranean. They come as the Earth experiences another exceptionally warm year.

Average global surface temperatures over land and sea were the second highest on record for the first five months of 2017, according to analyses by NOAA, NASA-Goddard Institute for Space Studies and the European Centre for Medium Range Weather Forecasting Copernicus Climate Change Service.

Only 2016 saw higher global temperatures due to a combination of a very powerful El Niño event, which has a warming impact, and long-term climate change caused by greenhouse gas emissions. So far in 2017 there has been no El Niño event.

Climate change scenarios predict that heatwaves will become more intense, more frequent and longer. It is also expected that the number of hot days and warm nights will continue to rise.

Europe

The Deutscher Wetterdienst (DWD), which acts as WMO’s Regional Climate Centre for Europe’s Node on Climate Monitoring, issued a new Climate Watch Advisory on 23 June 2017. A period with significantly above-normal temperatures and heat waves, at least for the next two weeks, is expected for most parts of the eastern Mediterranean (from Balkans to Caucasus and Middle East). The weekly anomalies are forecasted with up to +6°C (in a wider area around the Black Sea and Middle East with daily temperature maxima up to or above 40°C). This warm period could come along with thunderstorms, showers or forest fires, it said.

The heatwave originated in the Iberian Peninsula earlier in June as a result of very hot air moving up from the Sahara. DWD said that that due to the weekly forecasts the heatwave would now move from south-western and central Europe eastwards to the eastern Mediterranean during the next two weeks.

The Climate Watch Advisory is used as guidance for National Meteorological and Hydrological Services who are responsible for issuing forecasts and warnings. Meteorological services have also been providing information on air quality, UV levels and wildfire risk.

Iberian Peninsula

Extremely high temperatures of around 40°C contributed to the severity of the disastrous wildfire in Portugal which claimed dozens of lives. The Portuguese national meteorological service, IPMA, said that over the weekend, when the fire broke out, more than one third of its weather stations measured temperatures over 40°C.

Spain:

Spring 2017 (from 1 March to 31 May 2017) has been extremely warm, with an average temperature of 15.4 ° C, which is 1.7 ° C above the average of this term (reference period 1981-2010). It has been the warmest spring since 1965, having exceeded by 0.06 ° C the previous highest value, which corresponded to the spring of 2011. It has therefore been also the warmest spring since the beginning of the 21st century, according to the national meteorological service AEMET.

The marked contrast observed between the maximum temperature anomalies, which were on average 2.5 º C above the normal value of the term, and those of the minimum temperatures, which were only 0.9 ºC higher than the normal ones. A number of places broke temperature records for June for both maximum daytime temperatures and minimum overnight ones.

These include Granada airport, 41.5°C, Madrid Retiro 40.3°C and Madrid airport 40.1°C on 17 June. The peak if the minimum temperatures was on the 19th June, when Salamanca and Zamora had record overnight temperatures of 22.1°C and 23.7°C.

France

Fifty one departments in France have an amber alert for high temperatures on 20 June, according to Meteo France. Temperatures for Monday included 38°C for Bordeaux, 36°C forLimoges, 34°C for Mulhouse and 33°C for Paris, Toulouse, Brest and Lille, according to Meteo France.

A number of stations broke June records, including Cuers at 37.6°C and Toulon 35.3°C. Records for minimum night-time temperatures were also beaten (25.1°C in Montpellier, 25°C in Marseille) on Friday 16 June. Meteo France said that very high temperatures will continue until Friday 23 June, with temperatures between 32 °C and 38 °C in the afternoon, or more than 10°C above the average for this time of year.

Meteo France issued a probabilistic seasonal forecast on 23 June, anticipating above average temperatures for June, July and August, especially in southern Europe.

Other parts of Europe

Many other parts of Europe, including the United Kingdom, also witnessed above average temperatures into the low to mid 30°s. London Heathrow airport saw a temperature of 35°C on 21 June. The Met Office said it was the hottest June day since 1976 and the hottest summer solstice on record.

The town of Andernach, on the Rhine river, reached 37.1°C on 22 June, the same day as violent storms, hail, high winds and rain swept through northern and western parts of Germany, causing considerable traffic disruption and a number of reported casualties.

USA

Record heat has been reported in the desert southwest USA and into California. The US National Weather Service has warned that dangerous heat will continue through at least Friday 23 June in Nevada, Arizona, parts of California and Las Vegas.

Phoenix recorded 118°C (47.8°C) on 19 June. In the 11,059 days since the start of record keeping, 118°C heat has only been recorded 15 times. A number of flights to Phoenix Sky Harbour International Airport were reportedly cancelled because it was too hot to fly. Tucson, Arizona saw three straight days above 115°C (46°C). Las Vegas equalled its temperature record of 117°F (47.2°C). Needles, California, reported a new record of 125°C (51.7°C). Death Valley National Park recorded 127°C (52.8°C). Death Valley holds the world record for the highest temperature, 56.7°C recorded in 1913.

North Africa, Middle East and Asia

The temperature in United Arab Emirates topped 50°C on 17 May, with 50.5°C in Mezaira.

In the center of Iran's Kuzestan province in the south-east of the country, neighboring Iraq, temperatures reached 50°C on 15 June.

The heatwave in Morocco peaked on 17 May, when there was a new reported record of 42.9°C Larach Station in northern Morocco.

The high June temperatures follow above average temperatures in parts of the world at the end of May. The town of Turbat in southwestern Pakistan reported a temperature of 54°C. WMO will set up an international committee of experts to verify the temperature and assess whether it equals a reported 54°C temperature recorded in Kuwait last July.