In the panorama of gas turbines for energy production, a great relevance is given to performance impact of the ambient conditions. Under the in?uence of ambient temperature, humidity and other factors, the engine performance is subject to consistent variations. This is true for large power plants as well as small engines. In Combined Cycle con?guration, variation in performance are mitigated by the HRSG and the bottoming steam cycle. In a small scale system, such as a micro gas turbine, the in?uence on the electric and thermal power productions is strong as well, and is not mitigated by a bottoming cycle. This work focuses on the Turbec T100 micro gas turbine and its performance through a series of operations with different ambient temperatures. The goal is to characterize the engine performance deriving simple correlations for the in?uence of ambient temperature on performance, at di?erent electrical loads. The newly obtained experimental data are compared with previous performance curves on a modi?ed machine, to capture the di?erences due to hardware degradation in time. An active management of the compressor inlet temperature may be developed in the future, basing on the analysis reported here.