Rainstorms and a widespread power outage dampened what is typically the most important shopping week of the year for many San Francisco retailers.

The days leading up to Christmas are often described by store owners as a financial sprint to the finish line, when holiday sales peak and foot traffic is at its highest. But this year, persistent rain right before Christmas — combined with a major power outage on Saturday — slowed business at a critical time.

At Derby of San Francisco in the Haight-Ashbury neighborhood, manager Edith Mariscal said the outage left the store unable to operate.

"We just couldn't let people in. There's no lights and it gets really dark in here," Mariscal said.

Mariscal said the outage also prevented the store from accepting cash or processing transactions of any kind.

"We even scheduled more people than needed usually, and we had to send a few home," she added, explaining that staff had been brought in anticipating heavy holiday crowds. 

Much of the Haight-Ashbury retail district was left in the dark on Saturday before Christmas, known by retailers as "Super Saturday," with only a handful of businesses able to remain open thanks to backup generators.

San Franpsycho was among the stores affected by the combination of weather and the outage.

"We took a pretty big hit on Saturday. I think in combination with the power outage and the weather, it really discouraged people from being local," said S. Apollo Fisher of San Franpsycho.

Both San Franpsycho and Derby of San Francisco said that while overall holiday sales remained solid, business was noticeably slower compared to the same period last year.

"Especially via foot traffic, much slower," Fisher said.

As rain eased briefly on Friday, some shoppers went out to exchange or return holiday gifts, while others searched for post-holiday deals.

"(My mother) got me a pair of gloves and they're too big. I just want to exchange them," said Marina Munoz-Pendergrass, who was shopping during the break in the weather.

Others took advantage of discounts.

"[Macy's] had 40% discounted products, so I bought a top for my son. 40% off, can't go wrong," said Michael Chun.

With just a few days left in the year, retailers like Mariscal remain hopeful that sales will rebound as shoppers return.

"The classic black jackets are the most popular. But everybody can connect with different colors as well," Mariscal said.

PG&E said affected business customers will automatically receive a $2,500 credit for the Saturday power outage. Businesses that experienced losses beyond that amount can also file a claim.