The weekend was also busy with 500 visiting on Saturday and 300 on Sunday.
In Hastings people also headed to the pools for a cool dip.
1600 people decided on Monday that Splash Planet was the best place to cool down.
Frimley had 552 people through the doors, and Swim Heretaunga in Flaxmere had 140.
People also headed to the beach. Director of lifesaving at Westshore surf life saving club Brian Quirk said the beach was busy when he visited at 5.30pm.
He said regional patrols ended on Friday.
He said Westshore was a relatively safe beach to swim at, but it was important to always check for rips before swimming anywhere in the ocean.
The hot weather is set to continue until Friday, although it is not expected to be as hot as Monday's 35C scorcher.
Napier and Hastings will see temperatures in the high 20s Wednesday and Thursday, and hit 31C on Friday, before cooling down for the weekend, with 23C and 22C expected on Saturday respectively.