Heavy rainfall and flooding is possible in the metro-east and a flood watch remains in effect until late Saturday night.
The National Weather Service said 2 to 4 inches of rain may fall with some places possibly receiving heavier amounts.
Rain began falling Friday night after an unseasonably high of 70 was recorded at the St. Louis Downtown Airport in Cahokia.
Temperatures are expected to remain just a bit too warm for snow. The high Saturday is forecast to be 36 with a low of 33.
According to meteorologists, every inch of rain equates to 8 to 10 inches of snow. That means the precipitation could add up to more than 2 feet of snow if temperatures were just a few degrees cooler.
The outlook for Christmas Day calls for a high of 38 under partly sunny skies.