Europe: High temperatures forecast to persist across the region through at least July 22 /update 3

High temperatures are forecast to persist across southern and southeastern Europe through at least July 22. The affected area includes much of Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Hungary, Italy, Kosovo, Malta, Montenegro, North Macedonia, Romania, Serbia, and Slovenia. Temperatures in excess of 40 C (104 F) are possible in parts of the region over the coming days.

As of July 18, the respective meteorological agencies have issued the following high-temperature warnings across the affected region:

• Red high-temperature warnings (the highest level on a three-tier scale): Across Bulgaria; Dubrovnik, Knin, Rijeka, and Split regions in Croatia; Bacs-Kiskun, Bekes, and Csongrad-Csanad counties in Hungary; Basilicata, Calabria, Puglia, Sardinia, and Sicily regions in Italy; central and southern Montenegro; and parts of southern and southeastern Romania.
• Orange high-temperature warnings (the middle level on a three-tier scale): Across central, eastern, and southern Bosnia and Herzegovina; Gospic, Karlovac, Osijek, and Zagreb regions in Croatia; across most of Greece with the exception of Attica and the Cyclades Islands; Baranya, Fejer, Hajdu-Bihar, Jasz-Nagykun-Szolnok, Komarom-Esztergom, Pest, Szabolcs-Szatmar-Bereg, and Tolna counties in Hungary; Campania, Lazio, Tuscany, and Umbria regions in Italy; across Kosovo; across Malta; northern Montenegro; across North Macedonia; parts of eastern, southern, and southwestern Romania; Eastern Serbia, Pomoravlje, Southeast Serbia, and Sumdija regions in Serbia; and central, southeastern, and southwestern regions in Slovenia.
• Yellow high-temperature warnings: Across the rest of Bosnia and Herzegovina not under orange warnings; Attica and the Cyclades Islands in Greece; across the rest of Hungary not under red and orange warnings; Abruzzo, Emilia-Romagna, March, Molise, and Trentino-Alto Adige region in Italy; parts of eastern, south-central, and western Romania; across the rest of Serbia not under orange warnings; and northeastern and northwestern regions in Slovenia.

Further red, orange, and yellow warnings are in place across much of the region over the coming days. Officials could update and possibly extend the coverage of weather alerts over the coming days.

The high temperatures may result in increased energy and water demand and a heightened risk of heat-related illnesses, such as heat exhaustion and heat stroke.

The extended period of oppressive heat and dry conditions may produce ideal circumstances for wildfire growth throughout the region. Heatwaves also pose a threat to vulnerable groups - such as the elderly, children, pregnant women, and those with respiratory illnesses - due to the increased possibility of heat stroke or heat exhaustion during prolonged exposure to high temperatures. These health risks could also extend to relatively healthy individuals during significant heatwave events.

Very high temperatures may warp rail tracks and force passenger and freight trains to operate at reduced speeds. Road surface damage is also possible, and overheated vehicles may worsen traffic problems in urban areas where congestion is already a problem. Commercial trucking disruptions might occur as very high temperatures stress vehicles, making tire blowouts more common. Major flight disruptions are unlikely, but general aviation disruptions are possible, and some airfreight carriers could reduce cargo loads. High temperatures could lead to an increased demand for electricity, which might trigger localized brownouts or blackouts, exacerbating hazardous conditions when air conditioning is no longer possible.