Minimum wage in Montana will increase on Jan. 1. Posted at 11:07 AM, Dec 30, 2020 and last updated 2020-12-30 13:12:52-05 GREAT FALLS â Montanaâs minimum wage will increase from $8.65 per hour to $8.75 per hour beginning on Friday, Jan. 1, 2021. The state reports that an estimated 8,000 to 10,000 Montana workers, or about 2% of the workforce, received hourly wages less than $8.75 per hour in 2020. At the beginning of 2020, the minimum wage in Montana was raised from $8.50 to $8.65. The minimum wage is determined by taking the current minimum wage of $8.65 and increasing it by the CPI-U increase from August of 2019 to August 2020. The CPI-U increased by 1.31% (unadjusted) over the year ending August 2020.