The Met Office has issued a yellow thunderstorm warning for the whole of Northern Ireland, valid from midnight to 10am on Friday.

The alert warns that heavy showers and thunderstorms will move north across the region during Friday morning. Where storms develop, they will bring frequent lightning, hail and rainfall totals of 15 to 20mm in less than an hour. Some places will stay dry but those affected could see localised flooding and difficult driving conditions.

The Met Office cautions that surface water could overwhelm drains and that homes and businesses face a small chance of being flooded quickly. Damage from lightning strikes, hail or strong winds is also possible. There is a slight risk of power cuts and loss of other services. Motorists are advised to allow extra journey time, especially during the morning commute.

The thunderstorm warning follows several days of hot weather that pushed Northern Ireland close to its all-time temperature record. Thursday saw highs climb towards 31.3C in western areas, the record set at Castlederg, County Tyrone in July 2021. Coastal spots remained cooler in the low 20s. The Met Office confirmed heatwave conditions were met on Wednesday after 25C was recorded for three days running.

Across the border, Met Eireann placed an orange thunderstorm warning on Cork, Kerry and Waterford and a wider yellow alert on western counties. The Republic of Ireland record of 33.3C, dating to Kilkenny Castle in 1887, could be challenged. Meteorologist Gerry Murphy said cloud and thunderstorms off the west coast may keep a lid on temperatures however.

Weekend weather will begin a transition to more typical summer conditions. Cooler, fresher air will edge in from the west. Saturday will bring more cloud, breezy weather and showers to Northern Ireland. Sunday will see a more distinct change with temperatures falling to the high teens and further rain or thundery outbreaks.

Professor Graeme Swindles of Queens University Belfast said climate change is accelerating and that Northern Ireland can expect more temperature records to be broken. While hot summers have always happened, the baseline has shifted. He said the regions climate is buffered by the Atlantic but changes to storm patterns are causing problems. Adaptation is needed as summers trend warmer and drier and winters become wetter with high-intensity rain and wind, he added.