It is really hot. And if you want to buy an incredibly inefficient portable unit, one that will not cool your house that well and will use a lot of electricity, there is nothing to stop you. Anywhere in the country, you can do it right now. There are plenty of options online. If you want to install a proper, energy efficient system that will work better, cost less to run, and be better for the environment, then it depends where you live and what kind of home you have. I live in Camden, North London.