Weather: Northern Ireland basks on hottest day of year as temperatures hit 28C
Thousands of people poured onto Northern Ireland's beaches yesterday to make the most of the hottest day of the year so far.
Temperatures soared to a high of 28C in Castlederg in the west - making it hotter than Algiers.
Crawfordsburn Country Park in North Down had to be closed in the afternoon as it reached capacity, the PSNI said.
Meanwhile, the National Trust, which looks after Portstewart Strand, estimated that the popular beach had attracted at least 1,800 sun worshippers.
Last night forecasters warned that torrential rain and thunderstorms could bring flooding and disruption to power networks.
The Met Office, which issued a yellow warning, said hot air spreading north was expected to bring thunderstorms to parts of the province, with a possibility of up to 50mm of rainfall.
"Whilst most places will miss the worst, please be aware of the risk of localised flash flooding. Frequent lightning, large hail and strong winds could be additional hazards," a spokesman said.
"All of this could lead to some flooding of homes, businesses and transport networks. Disruption to power is also possible."
Staff at Belfast Zoo made sure the animals didn't suffer in yesterday's soaring temperatures - although some species were fine with it.
Curator Andrew Hope said: "Primates would sunbathe in that weather - very few of them would retreat to the shade."
However, the heat was a little much for some of the penguins.
"We've provided extra shade, put in some sprinklers and we would sometimes give the animals ice blocks and lollipops which they can lick to keep cool," he said. "The elephants have been getting a mud bath today in their mud wallow and the sea lions have been popping in and out of the water."
NI Water, meanwhile, warned of fines of up to £2,500 if people abused fire hydrants. It dispatched a team to carry out repairs after children set off some in the Laganbank area of Belfast.
"Some may regard this activity as harmless fun on a warm day, but fire hydrant abuse can have serious implications for customers who may be left with low or zero water pressure, or - even worse - the Fire Service may find that water pressure is insufficient to deal with a fire," an NI Water spokesman said.
"We would appeal to local community leaders and political representatives who have supported us in the past to continue to do so, and we would encourage the whole community to take a stand against fire hydrant abuse which has the potential to cause so much damage.
"Vandalism should be reported to the PSNI or to Waterline on 03457 440088."
Today is expected to be cloudy but dry in most places, with heavy thundery showers possible in the east in the morning.
Outbreaks of rain are expected to spread east tomorrow, followed by a dry Friday with sunny spells. More persistent rain is expected on Saturday, clearing later in the day.