· Queensland bakes
· Catastrophic conditions in SA, WA

As temperatures continue to soar across NSW, long traffic jams are causing havoc for motorists.

Those seeking respite from the heat at the Wet n’ Wild water park in western Sydney on Thursday instead found themselves sweltering in heavy traffic, the Transport Management Centre said.

The car park at the water park was full by 1pm (AEDT).

With temperatures set to hit more than 40C, people were expected to head to the beach across the state’s coast.

But those heading to the Royal National Park beaches also struggled against heavy traffic and a full car park at Garie Beach.

By lunch time, Sydney city temperatures had reached 35C while Penrith was sweltering in 36C heat, the Bureau of Meteorology said.

Dubbo in the state’s central west was expected to experience tops of 39C, with Bourke in the state’s upper west looked to be one of the hottest spots at 46C.

On the Pacific Highway in the state’s north, traffic queues of more than eight kilometres snaked through Ewingsdale, while there were jams five kilometres long at Macksville.

The worst delays were between Woolgoolga and Coffs Harbour where the southbound lane was backed up by 12km, causing delays of 80 minutes.

Motorists were being urged to allow extra travel time for their trips while paramedics warned beach-goers to stay safe on the water.

This time last year paramedics say they responded to a spike in triple-0 calls at beaches and pools, with people having jet ski accidents, getting caught in rips, and drowning.

“In the west of the state where temperatures of over 40 degrees are expected, dehydration and heat stroke are a real threat,” NSW Ambulance said in a statement.

“In these areas and across the state, if you need relief from the heat, stay inside in an air-conditioned environment, keep up your water intake and minimise the consumption of alcohol in the hottest parts of the day.”