Eight counties remain under a weather warning during a spell of high temperatures that have already surpassed May records.Temperatures of 30.5 degrees were recorded in provisional data on Tuesday, according to Met Éireann.Clare, Kerry, Limerick, Tipperary, Galway, Kilkenny, Laois and Offaly were put under a yellow warning between midday on Tuesday and 6pm on Wednesday.Met Éireann said maximum temperatures would exceed 27 degrees and night-time levels of above 15 degrees could be expected.It warned of water safety issues because of increased use of lakes and beaches, the possibility of forest fires, and uncomfortable sleeping conditions as well as heat stress.[ ‘It’s like Costa del Raheny’: Beachgoers in Dollymount make hay while the sun shinesOpens in new window ]Met Éireann said its station at Shannon Airport in Co Clare logged a May highest temperature of 28.6 degrees on Monday, surpassing a 1997 record of 28.4 degrees in Co Kerry.On Tuesday, those levels appeared to be surpassed in the early data published by the forecaster.Met Éireann’s station at Shannon Airport reported 30.5 degrees at 3pm, provisionally a new record.Higher temperatures were recorded in unofficial provisional observations at Met Éireann’s automatic climate stations (ACS) on both days, with Clonmel ACS recording 30.7 degrees at 2pm on Tuesday – although these figures can take longer to verify.[ ‘Extreme event’: Here is what’s causing record-breaking temperatures in Ireland and EuropeOpens in new window ]The forecaster said the hot weather would continue into Wednesday with top temperatures of 22 eegrees to 31 degrees, hottest in the Midwest and West.In Northern Ireland, the highest maximum temperature on Monday of 25.8 centre was recorded at Derrylin, Co Fermanagh. Tuesday had highest temperatures in the region of between 20 and 23 degrees.