Up to ten centimetres of snow could fall across Dorset on Sunday and Monday.
The Met Office has issued a yellow weather warning for snow all day on Sunday and Monday - but said that current forecasts may change before the weekend.
Temperatures are set to drop with rain turning to snow across the south west.
A Met Office spokesperson said: "There is a risk that a band of rain spreading from the south west during Sunday will turn to sleet and snow.
"There is the potential for accumulations up to 10cm in places and the public should be aware of possible disruption to travel."