It is part of Wimbledon and always has been.
More than strawberries and cream, freshly mown grass, Martina Navratilova's serve-volley, jugs of Pimm's and lemonade, the Royal Box, Pete Sampras' leaping smash, all-white clothing, the hill, the museum and that iconic old scoreboard, it is rain and the interminable delays it has caused that have so often defined the greatest tournament in tennis.
But that all changes Monday when one more of this hallowed venue's ancient traditions makes way for modernity.
For the first time, a Wimbledon tournament will begin without organizers, players and fans splitting their time between tennis and meteorology and a guessing game against the unpredictable elements of late June in London.
Centre Court's new retractable roof doesn't just alter the face of the All England Club's primary scene of combat, it could have a great bearing on the way the tournament plays out.
Those endless hours spent in the locker room waiting for the heavens to lighten have tested the nerve of many a championship hopeful.
"I think the roof is fantastic," said Henman, now retired, who took part in an exhibition to launch the roof last month. "Wimbledon is the most special tournament in the world and having this will make it even better."
There is still a school of opinion, however, that laments drifting away from the old ways.
In recent years Wimbledon has crept gradually into the 21st century, introducing equal prize money for men and women, revamping the players' locker room, using video review for line calls and abolishing the required curtsy for female players.
The roof is the biggest accession to a new order – and not everyone is happy about it.
Many of the old-timers believed the unpredictability of the weather, and the good-natured camaraderie between spectators and officials during enforced breaks, gave the tournament an extra something.
But tournament referee Andrew Jarrett is adamant that the new environment can make this year's Wimbledon the best ever.
"The focus will clearly be on the roof," said Jarrett. "And we are confident it will be a great success.
"We will come up against lots of different situations. One day, it will be bright sunshine with just one isolated shower and, another day, it will be pouring with rain all day long. We will have to monitor things carefully."
So then, a step into the unknown for an event that has always reveled in its traditions and is beloved for it.
"The tradition will always be here," said Jarrett. "The roof is a continuation of it, and will become part of Wimbledon history in its own time."