The humid conditions have proved ideal breeding conditions for the insects. And now there are even fears the problem could be made worse – by the Olympics.
Experts fear the crowds will put people's heads into such close proximity the lice will be springing from head to head like Gold Medal-contending gymnasts.
Ian Burgess, director of insect research and development at the Medical Entomology Centre, told the Evening Standard: "We have had lots of damp weather and our studies suggest this has caused a higher level of lice than normal.
"The weather has also meant more children indoors and in close contact which has increased the speed at which the infestation has spread.
"Currently our research suggests about 10 per cent of pupils in a school have nits, which in an average primary school is about 40 at any one time.
"Chances are this is also being passed on from these children to their siblings and even their parents, who in turn can pass it on to their colleagues at work and fellow commuters.
"Lice have also built up some resistance to treatments such as pesticides, so the incidence of lice has risen dramatically over the past few generations."
Dee Wright, who runs a north London company called The Hairforce which specialises in lice-busting treatments, said:
In this weather, there is a big pick-up, there is a lot around. We have heard from our clients, talking about schools where their children are, that there are real problems, and everybody is desperate for term to end so they don't have to deal with them.