Fire crews have managed to contain a blaze near Blenheim that's been burning since yesterday afternoon.

Principal Rural Fire Officer Richard McNamara said it's taken a lot of hard work by the 35 fire crews and five aircraft battling the fire on steep terrain near Vernon Station.

"We've got a big containment line around it now. It's held through the day, through high temperatures and the incoming north-easterly. We expect to hold that through this evening and put a night crew on it tonight.

"We're pretty please with the way it's gone today. It's been a lot of hard work put in by both man and machine. God willing we will hold onto it tonight and hopefully get back into some good shape tomorrow".

McNamara said the fire's already burnt through at least 25 hectares of scrub in the gully - 15 kilometres south of Blenheim.

He said 35 fire crews and five aircraft tackled the fire today, and a night crew will be kept in place overnight.