Why Is Britain So Hot?

As 'furnace' Britain slaps on another coating of suncream and applies wet flannels to the back of it's neck, more and more people are wondering just why it is so hot this summer.
Meanwhile, on the other side of the Atlantic, Canadians are pulling on the wellington boots and holding up umbrella's and wondering just why is it raining so much this summer. 
It seem's that when we have it hot, the Canadians get wet and vice versa as last year it was our turn to spend the summer months splashing in puddles and they turned up to work with the white strap marks and that is actually what happens, only one of us can be basking in high pressure at a time due to the Jet Stream.
The Jet Stream meanders up and down so depending on what side of the Jet Stream you find yourself, your weather is either wet and cold if you are above it while everything below it is warm and dry and until it moves, high and low pressures are trapped over that part of the globe.
The Jet Stream over our Eastern side of the Atlantic has been pushed right up as far as Iceland which means while we are hot and sunny, on the Western side the meandering see-saw effect means it is pushed right down so they are cold and wet resulting in the Toronto floods this week that saw 13cm of rain fall in just 2 hours and caused subways to flood and 50,000 homes lose power.
The MET Office say that the behaviour of the Jet Stream has changed dramatically in the past few years and it now meanders north and south more frequently where before it stayed relatively stable due to the warming Arctic where temperatures have increased at more than twice the global rate resulting in the disappearance of 1.3m square miles of sea ice.
Whether that means the Jet Stream being pushed down over there which means warm and dry we over here or we get the summer of floods will become apparent over the next few years.