Fire crews appear to have gotten the upper hand on a wildfire burning 18 kilometres northwest of Sooke, according to the Coastal Fire Centre.

The fire at Tugwell Creek was estimated to have grown to 100 hectares and was zero per cent contained by the end of the day Wednesday.

The fire centre now estimates it to be 84 hectares in size and says it is 50 per cent contained as of Thursday afternoon.

The blaze is suspected to be human-caused, but an investigation into how it sparked is still underway.

Seventy-four firefighters, seven helicopters, an incident management team and multiple pieces of heavy equipment and water tankers have been deployed.

Wind helped spread the fire through slash and into mature and juvenile timber, while embers sparked spot fires that also challenged firefighters.

"They're making progress on suppression and we're preparing for similar weather as yesterday, but hoping for better conditions," said Coastal Fire Centre spokeswoman Dorthe Jakobsen.

Crews have also had to deal with a lack of available water, with "not a lot" of creeks or ponds in the region, the fire centre said.

The wildfire has produced massive plumes of smoke that can be seen and in some cases, smelled around the Capital Region, with many taking to social media to report the odour.

Despite that, Environment Canada listed the Air Quality Health Index for the Victoria region as a 3, which is considered "low risk."

While it doesn't pose a significant health risk to the general public, Island Health said that communities closer to the active fire zone may be experiencing poorer air quality.

"Individuals who have respiratory problems such as asthma or chronic bronchitis, if affected by the smoke in the air, may wish to consider reducing strenuous outdoor activities or remain indoors," Island Health said in a statement. "They also may need to adjust their medications in the event the smoke is aggravating their underlying health condition."

The BC Wildfire Service lists the current fire danger rating for the South Island as "high," meaning forests fuels are very dry and new fires could start easily and burn vigorously.