To combat climate change and global warming, the adoption of solar generation has increased remarkably. At the end of 2021, there was 92.5 GW of solar systems installed in the U.S. In California, 25% of electricity was generated from PV systems currently. However, due to the nature of inverter-based resources (IBRs), the inertia of power grids has decreased noticeably which could jeopardize frequency stability in power systems. With the increasing number of wildfires all around the world, wildfire smoke impact on solar systems needs to be investigated and studied for power system operations. Besides the significant PV power generation reduction, this study observed special patterns of PV power output during wildfire smoky days. This phenomenon on PV systems caused by wildfire smoke is named the “Wiggle Effect” in this study due to the wiggling PV power output. Unlike the general power output reduction caused by the smoke, the wiggle effect has the potential to risk the frequency stability of the power grid due to the sudden change of PV power generation. This study investigates the wiggle effect and discusses the impact on power system stability for low-inertia trending power systems. The outcome of this study can provide a better understanding of wildfire smoke impact on power grid operation for system operators to develop frequency control practices accordingly.