A few days of rain are unlikely to be enough to save desiccated farms.

Scattered rain and even heavy falls are expected across much of the country throughout the weekend - bringing some respite for struggling farmers in Otago, Canterbury, Wairarapa and Hawke's Bay.

Primary Industries Minister Nathan Guy is keeping an eye on the weather - but he doubts the rain will be enough to stave off a full-blown drought.

"We would need quite a bit of rain now to turn things around. It's unlikely that we're going to get enough, although I'm always an optimist. But let's wait and see."