Alaskans can now consume weed legally in their homes. Getty

Alaska has become the third state in the United States to legalise marijuana.

Residents are allowed to smoke weed in their own homes but it is forbidden to smoke it in public.

"People will not be legally lighting up out in the park tomorrow," Cynthia Franklin, director of the state's liquor control board, said on Monday.

Anyone caught smoking it in public will face a fine of $100.

Weed has been quasi-legal in Alaska since 1975 after the supreme court ruled it was part of an individual's right to privacy if they smoked marijuana at home. However discrepancies in the law emerged when prosecutors criminalised people for smoking dope at home in 2006.

"For the people of Alaska, it's a day where all of this 'Is it legal?' or 'Isn't it legal?' is straightened out," Franklin added.

The second phase could see Alaska following Colorado's lead and issuing its first marijuana business licenses as early as 2016.

"It's really just the beginning for us," she said.

The next state to legalise marijuana will be Oregon.