SNIP
>A few years ago I had a holiday in Ontario, in August. If I'd wanted to, there were but 2-3 days where I could have sunbathed. And that's been true of every time I've visited, and the US, hot and sultry and grey.

Hot and sultry and grey in the U.S.? I don't know where you visited, but I've lived and travelled all over the U.S. and there are few locations that fit that description in the summer. Granted a slow moving front may pass through periodically but they seldom last more than a couple of days. Here in NC we typically have very sunny summers and in fact, it is typically sunny most of the time. In the very hot summer we may have afternoon showers but they seldom last more than a few minutes in the late afternoon/early evening and the mornings and early afternoons are usually sunny. The sunniest places I've been too have been Colorado, New Mexico, Arizona, and Wyoming. Where in the U.S. were you and what time of year was it? How long did you stay?