PHOENIX -- Crank up the heat: It's going to be plenty cold in the Valley this weekend.
Weather analysts are forecasting four days of freezing temperatures, starting Saturday night, running through Tuesday. The last time the Valley had four straight sub-freezing mornings was 25 years ago.
Rain also is expected to arrive between 9 p.m. and midnight Thursday.
Chris Kuhlman with the National Weather Service said it will be a struggle to reach 50 degrees Friday.
"It will be very cold. Some areas will see the mid-20s for lows," Kuhlman said. "Other areas will be right at the freezing mark and below. This is a very large system coming off the north Pacific and very cold.
"Right now it's going across California and then we have a reinforcing shot of cold air coming down from western Canada on Sunday and that will keep our area temperatures about 15 degrees below normal."
The cold blast cold wreak havoc with gardens. Give plants and trees a good deep watering beforehand -- that will help them fend off the cold.
Protect trees with cotton sheets, not vinyl or tarps. Stop by a thrift store and pick some up sheets on the cheap. Cover citrus trees from crown to ground. Pin together the sheets to get the job done.