I'm just back from the Cairngorm's, so not quite Ben Nevis. Yesterday (Tuesday) we had a very light dusting of snow, just enough to cover the grass down to about 800m. It's freezing at valley level and visibility is very good, blue skies all around. The wind has been very high all new year around 60mph dropped to 45mph today.
I wouldn't discount carrying axe and crampons, even with little snow it can get very icy. The ground is very wet and it's now freezing.
Should add, the forecast is to stay cold and clear till Sunday when a front will arrive bringing sleet or snow. Beyond that who knows.