How hot are electric home stoves?
Short answer: no, there's no standard scale.

First of all, I'm pretty sure it's common enough for stoves of varying power to use the same range of numbers. I see an awful lot of stoves that go up to 10 in the US, and I'm quite confident they're not all the same.

Second, the real property of a stove is its power output, not its temperature. You can clearly see this if you go look at gas stoves - they're described in units of power (BTUs in the US, hooray). The temperature resulting from a given power will depend greatly on what you're cooking. A burner with nothing on it will have a much higher temperature than one with a heavy pot of boiling water on it. To a lesser degree, the temperature will also depend on the environment - a cooler room with some air circulation will keep the burner a bit cooler than a warm room with still air.

So, if you really want to know what you're getting, you have to look up the power output of the stove - or failing that, maybe try to measure it yourself.