If you are in a month-to-month lease, your landlord can increase your rent as long as they provide written notice before the increase. If the increase is 10% or less, the landlord must give you a written 30-day notice of the rent increase. If the increase is more than 10%, your landlord must give you a written 90-day notice of the rent increase.
If you are in a fixed-term lease for more than 30 days, your rent cannot be increased during the term of the lease, unless the lease allows rent increases.