CABO SAN LUCAS, Mexico - Tropical Storm Julio continued to move up Mexico's Baja California peninsula Monday but was expected to weaken to a tropical depression.

The storm drenched the resort-studded southern Baja California with heavy rains Sunday as authorities evacuated more than 2,500 families living along riverbeds near the coast.

By early Monday, tropical storm warnings for the southern tip of Baja California were discontinued but remained in effect farther north on the peninsula's west coast from Punta Abreojos to Santa Fe and along the east coast from La Paz to Mulege.

The storm had maximum sustained winds near 65 kilometres per hour.

But forecasters expected the storm to weaken and become a tropical depression later in the day.

The U.S. Hurricane Center in Miami said Julio could dump 7.5 to 15 centimetres of rain on the normally parched Mexican peninsula, raising fears of flash flooding.

Most vacationers rode out the bad weather Sunday inside their hotel rooms, but some ventured out on shopping trips and excursions.

"They're very calm," said Jorge Castro, front desk manager at the hillside Hotel Finiterra. The 224 guests were warned to stay away from the ocean, but none made plans to leave early.

"They can see it's not a huge problem. Some have even gone out on activities, on tours, or sand biking," Castro added.

The storm was centred about 45 kilometres west-southwest of Loreto early Monday and was moving north-northwest near 24 kilometres per hour. Tropical storm force winds extended up to 110 kilometres from the storm's centre.

The hurricane centre said the storm should enter the northern Gulf of California by Tuesday.