I'm in Perth. I'd like to go SUPing on the Swan River in the city but only if it's calm and smooth. What is the max Wave Height and Wind Speed I should look out for as a good indicator for these conditions? Thanks.

In summer the WA wind is mostly easterly in the mornings and south west in the afternoon... unless its really hot, then its easterly all day.

So, if its hot I would go to Lucky Bay. If not and the sea breeze is in, I would go to Freshwater Bay, or Matilda bay.

Depends a lot on what kind of sup you've got. If its a laymans sup, or surf sup (flat overgrown mini mal), anything over 5knts wind speed, you're going to start having a less than pleasant time. I don't own one, but hazard a guess a race style sup (skinny/tippy) you'll be able to cope with a bit more.

The chop on the river is pretty much wind driven, so chop wise you'll get away with a bit more wind (10 knots starts to get mighty unpleasant), if you're chasing a work out. I tend to set out into the wind, then turn around for an easy cruise home with the wind on my back.