The performance of the reactor vessel auxiliary cooling system (RVACS) of a liquid-metal reactor is a function of the pressure difference between the cooling air inlet and outlet, of the air density variation along the flow path, and of the pressure loss and heat transfer characteristics of this path. The pressure difference between the air inlet and outlet as well as the RVACS inlet temperature may be affected by wind speed and direction. The objective of this work was to analyze the effects of wind on the performance of the RVACS of an advanced liquid metal reactor design based on the PRISM concept. Each stack of the reference RVACS design had two air inlets. The analysis showed that one particular wind direction had the most adverse impact on the RVACS performance. For this direction, in a two-inlet stack design, the net effect of a 27 m/s (60 mph) wind on the RVACS air flow would be a reduction of ∼15%; while in a four-inlet design, the net effect would be nearly zero. A 15% reduction in the RVACS airflow would increase the peak cladding temperature by ∼15°C. In reality, however, the wind direction fluctuates around an average direction, and the most adverse wind effect should be <15°C. The temperature at the inlet of the downwind stacks is affected by the outflow of the upwind stacks, but the effect is small. For an air temperature change of 164°C along the RVACS flow path, the maximum inlet temperature rise is ∼5°C. This would increase the peak cladding temperature by ∼1°C.