I was watching one of those more indepth forecasts a few days ago.
It said that the wind was changing, so that, instead of getting warm air from Africa, we would suddenly get atlantic, or northern air - i cant recall which.
...so the temp was sudddenly going to drop (as it just has) and then, apparently, the wind was going to change back again or somthing - so it was going to get warmer again?
I dont normally trust these things at all, but this one seemed a little more credible than the usual "its going to start to rain at 3:30" things.