While AquaZone's smaller indoor pool still operates in the colder months, the 50-metre pool is only open during summer.

Petition organiser Brooke Fleming said the outdoor pool was mainly used by lap swimmers and schools during that time.

"I started the petition just because I hear so many people that use the facility wanting more space," she told The Standard.

"Once the outdoor pool is closed, everyone that would normally use it comes indoors to the 25-metre pool and it's inundated."

The petition has received more than 200 signatures, with people voicing their support for the change to operating hours in the comments section.

"This directly affects my family. We all love swimming and there is not enough room in the indoor pool. Not good enough for a town the size of Warrnambool," one supporter wrote on the petition.

"When they close the outside pool it causes so much tension. The pool is overcrowded and being in the walking lane makes it impossible to do what you need to do with up to 11 people in one lane," said another.

Warrnambool Masters Swimming Club president Laura Tweddle said members would happily swim in the outdoor pool for an extended season.

"As a club we would prefer to use the outdoor 50-metre pool wherever available throughout the year for our sessions," she said.

While the season has been extended before, a Warrnambool City Council spokesman said keeping the outdoor pool open year-round would be too expensive.

"The cost of operating the outdoor pool is about $12,000 per week. To open it for an additional 34 weeks would cost very conservatively an additional $408,000," a spokesman told The Standard.

"During the summer months an average of 121 swimmers used the outdoor pool daily, contributing average revenue of $3206 per week.

"Use of the pool in colder months could be expected to be much less."

Despite this cost, swimmers say the council hasn't given the outdoor pool a chance.

"The people that are into their serious lap swimming have no issue hopping in a heated pool when it's raining, I think the council needs to understand that on a cold June day those people will still go," Ms Fleming said.

"The council have always said it would cost too much money but if people are healthy and well it actually costs the community less."