I'd say seersucker.  it retains shape well but is very cool.  linen i feel is a bit too flimsy, but plenty of people love linen suits so don't take my word for it.  maybe a very high quality coated linen of some kind would work.  I'm not sure where you're going or how hot it will be, but i wore a tropical weight wool poplin suit in 100 degree farenheit Florida heat and wasnt terribly uncomfortable.  Perhaps a linen shirt for added coolness?  might work for a less formal wedding, especially if worn with a suit jacket

I agree with FNB that a wool/mohair blend is the best bet.  I just parted with medium-dark grey suit with a faint light grey stripe in a plain weave of 85% wool/15% mohair that was my default dressy suit for the hottest of weather (I’m talking 90+ degrees and very high humidity).  The fabric was in the 7/8 oz. range but resisted wrinkling even when it got moist and was cooler than anything except a shirt-weight unlined linen suit that is not appropriate for court, weddings, funerals, etc.  When new it had virtually no sheen, but after a dozen years it did shine enough to be consigned to charity.  I’ve replaced it with a solid charcoal blend of the same proportions but in a heavier (9/10 oz) fresco type weave which has not yet been tested in the most brutal heat.  I’m sure wrinkling won’t be a problem, but we’ll see about coolness.  The best shirting I’ve found for the heat is a lightweight royal oxford.  Because of the weave it doesn’t show wrinkles and it breaths quite well yet is opaque; and with a spread collar and French cuffs it’s plenty dressy.

Some excellent suggestions so far. I will definitely be book-marking this thread.

Seersucker is an excellent idea, but I think it will be a bit too casual for this particular event.

The wedding will be taking place in Nigeria. I am expecting the temperature to be in the 30 celsius range. It's one of those weddings where I will have to be on top of my sartorial game. I was considering a window-pane suit (not sure yet if it will be gray or navy blue back-ground), one button, peak lapel. I'm going to start looking through the suggested books. There might be some window-panes.


With the suit, I was thinking of a plain soft blue or a white shirt. I think the window-pane is a statement in itself, so a pink shirt could probably be too much. I can be quite boring like that. I will look at the voile, jacquard and royal oxford suggestions.

Please keep them coming.

Have a great day,
Bolaji

I'm going to have a word with my tailor.

To be fair to him, he held up the fabric to the light and it looked like an open weave to me. Goes to show how much I still have to learn...

I was reading in Hardy Amies' book last night, and he says the best material for travelling is mohair, of 12-15 ounces. It does not hold wrinkles and is right for every situation. He said for summer a 9-11 ounce mohair is fine, although it will wrinkle a bit.

This was written in the 1960s, obviously.