Look out for flashes of silver as the females make nests called redds in the gravel to deposit her eggs. You can pick out the position of the redds in the river as the gravel is much lighter than the surrounding river bed. This is caused by the salmon effectively cleaning the silt off the gravel as it excavates the small trench.
Large males can also be seen defending territories and seeing off would-be suitors. One thing I've also found interesting is the story of the aptly named 'precocious parr'.
Parr are small male juvenile salmon. They remain in freshwater for one to four years, feeding on insects before changing into 'smolts' and heading for the ocean during spring of their second, third or fourth year.
The 'precocious parr' have a cunning tactic of getting in with the females. Due to their small size and sneaky manoeuvres, they're able to dart unoticed under the much larger mature spawning salmon and fertilize some of the newly laid eggs.
Why not check out some salmon spawning for yourself this weekend? The Wye and Usk Foundation are hosting a river walk this Sunday to witness this event and there are still places available. Give them a ring to book.
You can also check out our amazing archive clips of leaping salmon on the river Dee.
So, where are the other hotspots across Wales for watching salmon? We'd love to hear from you if you've caught a glimpse of their amazing acrobatics this autumn so drop me a line with your recommendations using the comment form below.