Long-Range (LoRa) is one of the main modulation techniques used for Low Power Wide Area Networks (LPWANs). Recently, it has been extended from the sub-GHz band to the 2.4 GHz Industrial, Scientific, and Medical (ISM) band, enabling the construction of a LPWAN that benefits from global interoperability without duty-cycle limitations. However, the coexistence of LoRa with the other wireless technologies of the 2.4 GHz ISM band is a challenging question. In this paper, we make the first performance evaluation of the interference between LoRa and Wireless Fidelity (Wi-Fi) transmissions, by analyzing multiple parameters: LoRa channel occupancy, deployment topology, LoRa physical layer parameters, and the frequency channels used. We also perform simulations to extend our experimental results to other configurations. The performance evaluation is achieved using a generic methodology that can be applied to other wireless technologies. Finally, we provide recommendations for the use and deployment of LoRa that will improve its coexistence with Wi-Fi.