Christina O'Haver, The Union Democrat

After an eventful weekend of hail, snow and below-freezing conditions, the Mother Lode will see clear skies and a slight increase in temperatures throughout the week.

Low temperatures will likely remain below freezing but will gradually climb to 32 degrees or higher by Sunday, according to the National Weather Service in Sacramento.

Meteorologists aren't expecting any precipitation in the Sierra Nevada foothills over the next two weeks.

The marginally warmer temperatures will be the result of a high pressure system moving over California from the Eastern Pacific, according to National Weather Service meteorologist Drew Peterson.

"I think the worst nights are behind us," he said.

Peterson attributed the statewide cold spell to frigid air moving in from Canada.

Light winds and clear skies have also contributed to chilly temperatures in the Mother Lode, he said.

"Typically, clouds act kind of like a blanket at night," he said.

Snow accumulation at higher elevations is another factor, causing a meteorological phenomenon known as "cold air pooling," Peterson said.

"Cold air pooling" happens when dense, cold air rolls down mountain slopes and settles at the base.

Peterson compared the current weather conditions with a January 2007 system, which brought record-breaking cold temperatures to areas in California.

Jan. 14 saw its record low that year, dropping to 15 degrees overnight. Monday's low temperature in Sonora was 20 degrees. Up the hill, in Twain Harte, the low was 19 degrees.

More Tuolumne and Calaveras county residents experienced freezing and bursting pipes over the past few days, keeping water district employees and plumbers busy.

"I've been turning calls away because we're all booked up," Debbie Waters, co-owner of Waters Plumbing in Sonora, said Monday.

Tuolumne Utilities District spokeswoman Lisa Westbrook said many of the calls to the district about broken water lines stemmed from customers not insulating exposed pipes.

TUD, Calaveras County Water District and plumbing companies often receive calls about broken pipes at vacation homes after homeowners have been gone for long periods of time.

"If you're not home … turn the water off, drain the pipes and use a sugar-based antifreeze in P-traps and in toilet bowls and tanks," Jamestown-based Sierra Plumbing owner Rob Walker said.

Homeowners may also benefit from keeping their heat running at 50 degrees while they are away, Walker said.

Heat tape, a hair dryer or a light bulb can be used to thaw frozen pipes, according to experts.

Homeowners may also want to insulate non-native plants in their yards to keep them from freezing overnight.

Rebecca Miller-Cripps, of the University of California Cooperative Extension Natural Resources Program, said even a bed sheet can be effective in insulating plants, although a framework may be needed to keep the cover from weighing down on them.

Miller-Cripps discourages people from pruning plants that are damaged by frost.

"We recommend that people do not cut off the frozen material until spring comes to create an extra layer of insulation," she said.