Temperatures in Powys are expected to plummet tonight to as low as three degrees celsius.
From 7pm until 10pm, temperatures are expected to be at six degrees celsius, but will likely drop to five degrees celsius at 11pm.
The Met Office is expecting air temperatures from 1am on Tuesday to be at four degrees celsius, until 5am.
Temperatures could reach as low as three degrees celsius at around 6am in Powys, and are not expected to go higher than seven degrees throughout the whole of Tuesday.