Answer:

Around 8 over the river near Como, it's a private fireworks display (how mysterious).

Around 8 in Kalamunda, it's the Kalamunda Show.

Around 8.30 in Peppermint Grove, PLC is celebrating their centenary.

Around 10pm in Kwinana, Perth Motorplex is celebrating John 'The General' Day's 50 years in speedway.