Historic libraries were built to house paper-based collections with cultural heritage values. A balanced indoor climate is required to preserve these collections against the agents of deterioration. This study examines the indoor climate of historic Tire Necip Paşa Library and chemical degradation risk of manuscripts in two periods: pre- and post-restoration work. Indoor air temperature and relative humidity of the library were monitored for one year in 2014-2015 and 2019-2020. The riskiest months, i.e. May to October, determined in pre-restoration, were reanalyzed post-restoration. Then LM and eLM calculations were made for chemical risk assessment of manuscripts. Calculation results show that the risk of chemical degradation is minimized. The majority of results indicate a low risk of chemical degradation.