Weekend Promises Heat, Hot Cars : Weather: Porsche Parade rolls into town along with high temperatures and increasing humidity.

The weekend will begin with hot cars at San Diego Jack Murphy Stadium today and end with hot and humid weather Sunday, officials said.

The hot cars come courtesy of the 37th Annual Porsche Parade, one of the largest gatherings of sports car enthusiasts in the world, said Margie Smith-Haas, an event organizer.

The free convention of cars will feature more than 400 models of Porsches, on display today from 8 a.m. to 4 p.m., including restored classics and the new Porsche 968, Smith-Haas said.

The weather also will shift into high gear this weekend, with high temperatures and humidity subtly increasing each day, said Wilbur Shigehara, chief forecaster for the National Weather Service in San Diego.

By Sunday, the hot temperatures and high humidity will be felt throughout the county, he said.

The expected increase in heat and moisture stems from a high-pressure system in Mexico that will force humidity over the mountains and deserts toward the coast, Shigehara said.

According to Shigehara, the deserts might be the last place to visit this weekend. With temperatures there expected to peak between 105 and 111 degrees plus the humidity, safety precautions should be taken seriously, he said.

“It’s just not a good place to be,� Shigehara said. “If you do go, take plenty of water.�

On the other hand, the beach--a good place to be that already has plenty of water--will bask under sunny afternoon skies and warm temperatures this weekend, Shigehara said.

Temperatures at the beach will gradually increase a few degrees each day this weekend, with a high mark of 75, expected today, Shigehara said. Swimmers and surfers will enjoy 70-degree water temperatures, he said.

In the coastal section, including downtown, temperatures will reach 80 degrees and climb to nearly 85 the rest of the weekend, Shigehara said. At night, the temperature will fall to 66 degrees, he said.

The inland areas will have high temperatures in the 90s this weekend, with a high of 95 Sunday, Shigehara said. The low temperature will be 62 degrees at night.

The high night temperature will climb in the mountains this weekend, starting at 85 degrees today, reaching an 88 degree summit Saturday and peaking at 90 degrees Sunday, Shigehara said. The low temperature will fall to about 62 degrees at night all weekend, he said.