Rubbish It's certainly possible to fly 100 hours in the UK in one month. In the past i've know a few instructors that have done it on a regular basis.
Even in the current my flying school not that busy environment the full time instructors are getting 40-60 hours logged a month and the only reason that it is so low is due to lack of punters not crap weather.
However you must make sure that when you have a good flying day you really have to get the hours flown to make up for the days when the weather is poor. I also wouldn’t dismiss flying at night either (which I wouldn’t say is a bad idea anyway).
Having flown in both florida, LA and the UK I would agree it is easier to log the hours in other parts of the world but a 100 hours in a month in the UK is certainly achievable.