Vesuvius had been wearing a bright white collar, snow encircling the volcano's crater. Flakes were still falling as Monday turned into Tuesday and the stewards locked up the big yellow gates of the San Paolo.
When they open next, it will be in anticipation of perhaps Napoli's most glamorous fixture for nearly 20 years, with a place in the Champions League quarter-final at stake, and Chelsea the guests, next Tuesday.
With a 2-0 victory over Chievo on a cold night, Napoli had got their mojo back. It was high time, too.
The win was their first in six Serie A outings, which, coupled with Roma's defeat the same evening, moves Napoli within a point of sixth place, with the possibility of climbing up to fifth if they can conjure three points at Fiorentina tomorrow. That would still leave plenty of catching up if they are to repeat this season's compelling adventure in Europe's principal club competition.
Nonetheless, Walter Mazzarri, the head coach, felt emboldened, after goals from Miguel Angel Britos and Edinson Cavani had sealed the three points, to pronounce "it has been a great year".
Eliminating Manchester City from the Champions League and emerging to the last-16 stage has clearly been the season's highlight so far. And though Mazzarri would not say so, even when pressed, this might not be a bad time to be inflicting on Chelsea the full, ferocious ambience of the San Paolo. The London club look especially brittle at the moment.
Mazzarri acknowledged fatigue had been bound to affect his squad at some point in a campaign with so many more fixtures than Napoli are used to.
"I have sometimes lost track of what day it is," he said. Symptoms of tiredness were apparent by the end of January; it is not just because of involvement in three competitions either. Napoli's first XI is heavy with South Americans, many of whom had a shorter summer break because of the Copa America.
Against Chievo, Mazzarri glimpsed some encouraging antidotes to exhaustion. The midfielder Walter Gargano had been full of running and when the Uruguayan is at his busy best, his energy has a contagious quality.
Ezequiel Lavezzi, though short of goals, certainly caught some of it. The industrious Argentine also provided good news yesterday, by hinting strongly he wanted a long-term future in Naples, in spite of a long list of potential admirers.