Laws Terminating the Lease – Either party can terminate lease with a 30-day (1-month) notice and a 7-day notice for weekly leases. [1]Rent Increases – Landlords must give a 15-day notice before raising the rent amount. [2]Source§ 70-24-441§ 70-26-109Sample Montana Month-to-Month Lease Montana Month To Month Lease Agreement Template