Gardaí, Cork County Council and the HSE are urging people to park legally when visiting beaches, beauty spots and public amenities this coming weekend, so as not to block access to emergency services.
The appeal comes on the back of scenes in Cork and Wicklow last weekend, which saw motorists turned away from popular beaches.
Last Sunday, traffic was "hugely congested" on the way to Sandycove, Garrylucas and Garretstown beaches, as well as Dock Beach in Kinsale.
With no parking available, and potential access for emergency services limited, gardaí began to ask motorists to stay away from the mid-afternoon onwards.
However, they did not clear those already on the beaches.
Gardaí said that recent good weather has led to an increase in "dangerous illegal parking" at beauty spots across the country.
Assistant Garda Commissioner Michael Finn said officers dealt with numerous parking issues last weekend.
"We must all park our cars legally and safely. Parking irresponsibly can force wheelchair users and people pushing buggies onto the road, which puts them in harm’s way.
Commissioner Finn said gardaí would be policing beaches and amenity areas again this weekend to ensure legal parking.
"On the spot fines will be issued in relation to any illegal and dangerous parking,” he said.
"If you are paying a visit to the coast this weekend, take one moment to think about where you park your car. It could be lifesaving," said Cork County Council Chief Executive, Tim Lucey.
Mr Lucey said emergency services, and the fire service in particular, had been delayed in responding to some recent emergencies because of poor parking.
"Pease consider an alternative location if the area is already crowded and make the right decision," he said.
Though the weather this weekend is unlikely to be as fine as it was last weekend, gardaí encourage anyone planning a trip to organise their journey beforehand and think about how best to park legally and safely.
Saturday will be a largely dry day with sunny spells, according to Met Éireann, though it will become gradually cloudier from the west as the day goes on.
There is also a chance of patchy light rain or drizzle in the southwest later on Saturday evening.
Temperatures of 15C-19C are forecast, with slightly cooler conditions in the south-west.
On Saturday night, patchy rain will give way to showery outbreaks that will extend across much of the country from the southeast.
The weather looks set to change dramatically on Sunday, with Met Éireann forecasting thundery showers and longer spells of rain across the country.
Temperatures of 14C-16C are expected, with mostly moderate northeasterly winds.
Sunday night will be mostly cloudy, with temperatures dropping to 9C-12C and thundery downpours continuing.