It's up to you for PRMC, but remember when you are not actually doing the physical aspects, you will need a change of civilian clothes for each day you are there. ie; At least four shirts, socks & underwear. Possibly at least two pairs of trousers & likewise a couple of ties. If the forecast is cool but dry, a jacket is probably better than a coat as it's smarter, but it's not essential until you join.
For POC, definitely take at least one jacket if not a suit.