The temperatures in the Los Angeles-Metro area were expected to reach high 80s Saturday, creeping up to the 90s by Sunday and into Fourth of July.
As for the Valleys and the Inland Empire, things were expected to get even hotter with the forecast predicting temperatures in the triple digits Saturday and well into next week.
Thousands of heat savvy Southlanders packed Raging Waters in San Dimas on Saturday, attempting to beat the near-100-degree weather at the water park.
Health experts advise whether you're working outside in the heat or playing in the water, hydration is the key to staying safe in the sun.
"It can be somewhat misleading if you're hanging out by the water," said Mary Papadopoulos with Raging Waters. "You definitely need to drink plenty of water. Stay hydrated."
Earlier Saturday morning, many in Pasadena tried to beat the heat by getting up early to exercise.
Others said they're opting to stay indoors to dodge the sun.
"Sit in front of the fan, open all the windows. Living in the hills, it's a little cooler than down here, so we have a breeze going all day long. And if that fails, we do have an air conditioner we're going to turn on," said Altadena resident Susie Rogers.
Raging Waters is open from 10 a.m. to 7:30 p.m. through the holiday weekend.