What's now being described as a "monster fire" has erupted in northern California - growing in size overnight by an area roughly as big as Hamilton.
Fire crews say only 2 percent of it is under control - and that's just one of the fires they're fighting, CBS reports.
The fast-moving flames in northern California kept fire crews busy on Saturday (local time). Gusty wind conditions fuelled the blaze and by Sunday morning the so-called "county fire" had exploded.
The night sky just outside Sacramento was lit up as the fire tore through more than 6000 hectares, threatening dozens of structures and forcing evacuations.
- California fires: Emotional reunion as men find family dog thought dead
- Californian hero filmed rescuing rabbit as wildfire rages on
- California wildfires forces 190,000 from homes
Just one county over, fire crews were making headway on the Pawnee fire after it burned through more than 5500 hectares and destroyed 22 structures in just over a week. Seventy percent of the fire was contained, but over the weekend high winds pushed the fire over the containment line.
It's the same in Colorado, where high temperatures and high winds are fuelling the fire. So far it has burned through more than 16,000 hectares. Around 2000 homes have been evacuated because of it.
Around 300 kilometres west, Colorado's biggest fire continues to rage a month after it first broke out.
On Saturday authorities arrested Jesper Jorgensen and charged him with arson in connection to the Spring fire.
A month after it broke out, the fire has scorched more than 19,000 hectares, and according to fire officials it could be another month before they're even close to containment.
It has cost more than US$26 million to fight, and with the beginning of the fire season only just beginning the forecast is expected to get warmer, with limited rain.
CBS News.