Possible weather in July?

Ok, those of you who know me, already know that I have a particular interest in the weather. Don't ask me why, I don't really know; but I can remember watching the forecast quite intently even at a relatively early age in my parents' house. At my work, some of my colleagues tend to joke about it all, but hey- I am simply interested!

So, that brings me on to my current thought: What will the weather be like in July in Finland? Well, I've some experience already of the July/August type of weather in St Petersburg. There, it can be very hot, in the low 30's C, for a sustained period of up to two weeks at a time, then suddenly break down and become relatively cool and damp for days too, around 15C. Looking at the sites I have on the web, it appears we can expect much of the same sort of weather in southern Finland.

Can anyone with direct experience of Finland's summer weather help me out here? Certainly, if we are lucky enough to get weather in the high 20's or even low 30's, we'll be doing well, I know! You see, in Scotland, such temperatures are almost unknown. On top of that, we don't really often get settled weather for a sustained period. Oh well, I have already started praying to the weather Gods!