The festival sees musicians perform for free all over the city, with a ticketed event aboard the Lakeland Queen.
There will be a strong focus on youth, with international blues artists Isaiah Brunt and Andy Phillips holding youth workshops as well as performing.
Local musician Peri Grant has performed at every festival since it began with his band Hammer On.
He said the festival had become a fixture on the national music scene.
"We get a lot of people coming down from all over New Zealand and they come up especially for the blues festival.
"It has been steadily growing, a lot of it is just the weather, but they've arranged the gigs now so all the daytime stuff is when it's a bit warmer, and as it starts to cool off a bit they ship us inside."
He said the festival had a great vibe.
"You've got a captive audience, whereas when you are playing in a bar or restaurant and its not blues week you've got to work really hard to keep people's attention."
The festival also provided a platform for emerging musicians, he said.
"There is a lot of local talent, a lot of it goes unrecognised and not just seasoned musicians, there are all these young guys," Mr Grant said.
"There's a lot of talent out there that never gets the chance to get up and do things."