Dynamic line rating (DLR) is an emerging technology that can remove strict power transmission constraints and potentially reduce investment costs in new generation technologies in a microgrid. By implementing dynamic rating into distributed generation sizing and placement problem, it is possible to reduce the investment costs on new distributed energy resources by achieving improved optimal power flow results as compared to planning without considering DLR. This paper explores the possibility of complementing a model for optimal siting and placement of the distributed energy resources in a microgrid with the dynamic line rating. Implementation of DLR has shown a decrease in investment costs as well as a reduced number of installed generators as opposed to the solution without DLR implementation.