What's happened to my plants?

Some of my plants are not looking too healthy this year

Would appreciate your help identifying the problems

I'm quite new to Hydrangea, but a few of them in planters are doing this:


Lilac:



Rhododendron (sun damage or something more sinister?):



Another Lilac (only the new foliage seems to be affected, so could be sun damage?):

 

It looks more like fungal disease than drought or sun damage, @merleworld. Especially the last two. If you can prune them back to healthy growth and dispose of the affected leaves (and any on the ground) then give them a dose of systemic fungicide, that should do the trick!

 

Looks more like scorch to me, caused by moisture on the leaves acting like a magnifying glass for the sun to burn through.

 

If the leaves were just marked I'd agree, dai, but the way they're curled and powdery-looking, my money's on fungal infection.
http://www.gardeningknowhow.com/ornamental/shrubs/lilac/common-lilac-problems.htm
https://www.rhs.org.uk/advice/profile?PID=573
http://www.hgtv.com/outdoors/flowers-and-plants/trees-and-shrubs/a-hydrangea-problems-primer
But only merleworld can tell us if it's likely to be rain/sun damage....

 

The last two pictures look like wind scorch to me.

 

Thanks all. To clarify, they aren't powdery at all.

I'll remove/spray the hydrangeas but I agree that the others look more like scorch/sun damage so will leave.