Northern Ireland has recorded a second official heatwave this summer after temperatures in Castlederg, County Tyrone, stayed above 25C for three consecutive days. The Met Office heatwave threshold requires a weather station to reach at least 25C for three days running.

The Castlederg station logged 26.4C on Sunday, 25.1C on Monday and 25.7C by lunchtime on Tuesday. The same location also met the threshold in June and holds the Northern Ireland temperature record of 31.3C set in July 2021.

Inland areas are expected to remain hot for the rest of the week, with temperatures above the seasonal average, before cooling slightly towards the weekend. Coastal spots, including Portballintrae in County Antrim, have been several degrees cooler due to sea breezes.

A sharp temperature drop is forecast for Sunday as cooler North Atlantic air moves in. Daytime highs in Northern Ireland could fall to around 13C, well below the average for late July, and the change will end the current hot spell.

The Republic of Ireland remains under a heat warning for most counties until Friday and a national heat advisory until Saturday. A hosepipe ban and water conservation order will start in six counties on Thursday and remain for six weeks. Irish weather service Met Éireann has warned of risks including heat stress, forest fires and water safety issues.

The Met Office outlook for later July indicates predominantly dry conditions with high pressure, but temperatures will be less hot than recent days, with any showers confined to the far north.