A cold front will keep temperatures cool and bring a chance of light rain to the San Francisco Bay Area Wednesday night into Thursday, but conditions are expected to dry out by the time trick-or-treaters take to the streets on Halloween night. The only exception: Persistent showers may occur in the North Bay.

After a brief respite in rain, a stronger system is poised to deliver a second round of rain Thursday through Friday. The storm door is open and the Bay Area is finally getting notable precipitation, the National Weather Service says.

“This is the largest rainfall we’ve seen so far this season,” said Dial Hoang, a meteorologist with the weather service’s Bay Area office.

The two showers are moving into Northern California as a low-pressure system develops off the coast of the Pacific Northwest. While low pressure remains north of California, a cold front associated with the system will extend into the state Wednesday through Thursday. A second cold front will have greater impacts on the region Friday through Saturday.

High clouds began filling the sky over the Bay Area Wednesday morning, signaling rain is on the way. The first showers are forecast to arrive in the North Bay late Wednesday evening, with rain spreading south of the Golden Gate and reaching San Francisco and Oakland around midnight. The South Bay will see rain early Thursday morning, Hoang said.

The good news is that conditions will likely dry out across most of the area Thursday afternoon, just as trick-or-treaters start donning their costumes. The outlook isn’t as good for the North Bay, where light scattered showers could continue into Thursday evening. Fortunately, showers are likely to be light and you may not even need to open your umbrella. “We may only see a few hundredths of an inch in the North Bay on Thursday evening,” he said.

Precipitation totals from the first cold front are expected to be generally small, with most areas picking up a few hundredths to 0.1 inches. The North Bay Valleys, Oakland, San Francisco and western San Mateo County could see up to 0.25 inches, while the North Bay Valleys have a chance to record up to 0.5 inches, Hoang said.

The second cold front is the wetter system. The forecast shows it arriving from Friday to Saturday morning; Some uncertainty remained on Wednesday about the exact timing. From Friday to Saturday, areas south of the Golden Gate are forecast to see 0.5 to 0.75 inches, while the North Bay could see 0.75 to 1 inch, Hoang said.

Temperatures have remained below normal in recent days and the cold weather will continue into Saturday, the weather service said. On Wednesday, afternoon highs are expected to be 5 to 10 degrees below average, with mid to upper 60s inland, temperatures around 60 to 62 degrees in San Francisco and Oakland and upper 50s along the Pacific coast. Thursday and Friday will see similar afternoon highs, and temperatures will likely drop on Saturday before warmer weather arrives on Sunday.