With daytime temperatures on average above 70, this could be the third hottest January in Tucson's history.

The unseasonably warm temperatures are due to what is called a blocked weather pattern, said meteorologist Mike Leuthold, who is a researcher and lecturer at the UA's Department of Atmospheric Sciences.

“That means the jet stream is not moving anywhere," he explained. "The jet stream has not moved for probably the last six weeks.”

While this blocked weather pattern is making the Southwest heat up, it’s also what’s causing arctic-like conditions across the East, according to Leuthold. But he said he expects temperatures nationally to return to normal by this weekend.

“The forecast do indicate that the blocking pattern is going to break down, and maybe even some rain showers in Tucson by this weekend," he said.

Leuthold said it’s too early to pinpoint why this blocked weather pattern occurred, but some scientists believe rising sea temperatures could be a cause.