I have a stainless steel set that was originally off an Apollo lady's 3-speed. You never know when you're going to get caught in a downpour. Even though Australia is a fairly dry climate, when it does rain, it comes bucketing down. Sydney has twice the annual rainfall of London, but has a lot less "rain days".
The mudguard is one of those things that you don't "need" all of the time, but when you do need them, you'll be glad that you had them fitted. Also, I agree with ensuring that there is plenty of clearance between the mudguards and tyres, as mud, sticks, dirt, etc can clog them up and if there is insufficient clearance, you can break stays, guards, or just make your trip very hard going.