On Thursday, a high of 28C was recorded at Kew Gardens in London, a temperature which broke the previous record for May 1 which was 27.4C at Lossiemouth in Moray in 1990.
NI however could only muster a high of 18.1C, recorded at Killowen.
Residents in north Belfast were also hit with a thunderstorm in the early hours of Thursday morning, with locals reporting loud thunder and flashes of lightning.
Cloudy and occasionally showery conditions have lasted throughout the day in Northern Ireland, with drier weather becoming more prevalent as the day progressed.
It comes after NI recorded it’s hottest day of the year on Wednesday, with temperatures reaching a high of 23.6C in Castlederg.
People enjoying the sunny weather at Helens Bay Beach on the 30th April 2025 (Luke Jervis/Belfast Telegraph)
The warm weather had seen people flocking to local beauty spots to make the most of it as the Met Office warned of a downturn later in the week.
Forecasters have predicted a bright start to Friday in NI, with cloudy weather to follow later in the day.
Some sunshine is due to develop throughout the afternoon, with a maximum predicted temperature of 15C.
The weekend will bring some showery rain for a time on Saturday, with conditions remaining dry otherwise, with some brightness and cloud.
Temperatures are expected to remain in the teens.
Across the Irish Sea, the Met Office said conditions are expected to remain warm and sunny, dipping only slightly to around 26 or 27C.
Temperatures are expected to ease by Friday and Saturday will bring cooler conditions of 14C to 18C across the UK.
The NHS also reported that searches for hay fever advice had doubled from Monday to Wednesday.
Duncan Burton, chief nursing officer for England, said: “Most people will be able to manage their symptoms with medication that is available off the shelf from community pharmacies and supermarkets, and the NHS website has more advice on how to deal with the discomfort.”
Watch: Thunder storm rumbles over north Belfast
The weather has prompted warnings around the potential for wildfires, as well as further safety guidance on swimming in open waters.
It follows an incident in which a 16-year-old boy died after entering a lake at Colwick Park, Nottingham.
The got into difficulty while swimming in the area and his body was found a few hours later.
Nottinghamshire Police Chief Inspector David Mather said: “While work is now under way to understand how the boy came into difficulty, I would like to take this opportunity to highlight this case as a reminder of the devastating consequences of entering open water – regardless of whether people do so deliberately or inadvertently.
“As in this tragic case, open water can have hidden dangers that can prove fatal and I would urge anyone who spends any time on or near open water to use this case as a devastating reminder of that – particularly during the recent warm weather we have been experiencing.”