The UK
I believe has the highest number of tornadoes per unit area of land anywhere outside the USA. Except of course that's just a statistic, and is countered by two factors:

1 - we've got bugger all land area compared with the US, and
2 - most of the tornadoes are little weedy funnel clouds, and rarely do any damage.

We don't really do extreme weather here, thankfully. Look at this so called heatwave - we're getting to over 30°C and the nation is on alert. Many parts of the world have summer temperatures higher than this routinely. It's just that they're used to it.
( K2k6 has a proper job these days, Thu 2 Jul 2009, 8:28, Reply)