London 2012 chairman Sebastian Coe admits the adverse weather conditions are proving "quite a challenge" as the Olympics edge closer.

The Games could be one the wettest of any summer Olympics if the rain continues and the long-term forecast is for changeable conditions.

Coe admitted today that the weather is causing logistical problems for organisers, but pledged that contingency plans are in place to deal with issues.

"This is a challenge," he said, speaking at the first LOCOG daily briefing.

"I have joked in the past about putting a roof across the whole country, but let's be clear, this is actually proving quite a challenge to us.

"We have got waterlogged sites, resurfacing that is taking place in some areas, particularly in some of the more sensitive and rural sites, Greenwich Park and Eton Dorney.

"We're laying down a trackway and services for spectators and vehicles now and through the Games. Now we are building additional shelters for our workforce.

"At the risk of sounding a little bit like a father about to issue their kids off on an outward bound trip, let me make the obvious point that we are a northern European country.

"People do need to be wearing the right footwear, the right rain-proof clothing and sun screen."

Those attending events at rural venues have been advised by organisers LOCOG to wear wellies and Coe says the organisers are "making sensible and prudent judgements" to keep the Games on track.

"We of course do have contingencies across the whole project," he said.

"You won't be surprised when we tell you we have contingencies in sport and we have the contingency of extra days available to us in rowing and the equestrian sport. That is the last resort, of course.

"We have got an alternative sailing course available to us in Weymouth and we have, of course, the famous roof at Wimbledon.

"Then for those hardy souls that reside in track and field, hockey and triathlon, it is pretty much business as usual."

Despite weather issues, Coe insists everything is on schedule ahead of the opening ceremony in 10 days.

The former athlete also dismissed concerns that implementing contingency plans will incur extra unplanned costs.

"They are contingencies, they will have been budgeted for," Coe added.

"That will have been incorporated within the budget. We're clear about that.

"It is shelters, it is tracking, it is allowing our contractors and construction teams to get across waterlogged land. We're not talking much more than that."