Many of the field's 211 snow guns were fired up for the first time last weekend, but warm temperatures on Monday and yesterday made snowmaking impossible.
NZSki chief executive James Coddington said last night a decision would be made today about whether the field would open on Saturday as planned.
He described the weather as "changeable".
"[On Monday] night, it was predicted to have been -1degC, but we had an inversion layer in the valley and it was actually 6degC.
"At this time of year, it's hard to predict, so we're not predicting anything - we're just hoping."
Despite the spanner thrown into the works by the weather, Coronet Peak staff are working hard preparing for opening day.