Nanoresonators are crucial elements of various nano-electromechanical systems for the development of ultrasensitive sensing, efficient signal processing, biological detection, and so forth. Implementing methods that facilitate the wide tuning of the resonance frequency is beneficial for many of these applications. Ultrathin Si nanoresonators (width ~10 nm, length ~100 µm) can exhibit a wide electrostatic tunability of resonance frequency, which can be used for the easy electrostatic compensation of the thermal drift in resonance frequency among many other potential applications. How this tunability is impacted by temperature variation is a pertinent issue in many potential applications of tunable Si nanoresonators but currently remains unknown. In this study, we experimentally investigate the temperature dependence of the electrostatic tuning of a Si nanoresonator of ~80 nm width and ~200 µm length across a temperature range of 100–300 K. The results show significant decreases in electrostatic tuning range, efficiency, and resonance frequency tendency with decreasing temperature. We provide an approximate thermo-electromechanical model to describe this behavior and discuss how a dual tuning strategy by gate voltage and temperature can potentially bring further opportunities in terms of on-the-spot adjustment of the nanoresonator’s frequency as demanded in specific applications.