Abstract: Alternating current (AC) series arc faults are a major cause of electrical fires. Atmospheric pressure and wind speed are two key factors that affect low-voltage AC series arc faults. However, their coupled effect is not well understood. In this study, a two-dimensional axisymmetric magnetohydrodynamic model is built using COMSOL Multiphysics. An orthogonal experimental design is adopted with three pressure levels (60795, 81060 and 101325 Pa) and two wind speeds (2 and 4 m·s⁻¹) to investigate the temperature field, electrical characteristics, and energy evolution of arc faults under coupled conditions. The results are evaluated in terms of the average temperature, temperature integral, root mean square values of the current and voltage, and arc energy. The simulated arc voltage matches the zero-current characteristics and the overall trend observed in the experiment. The results show that wind primarily lowers the temperature of the peripheral region by improving the convective heat transfer near the arc column. Its effect on the core region is limited. At 101325 Pa, increasing the wind speed from 2 m·s⁻¹ to 4 m·s⁻¹ reduces the root mean square voltage by 7.1% from 63.997 V to 59.461 V. In contrast, the root mean square current stays within the narrow range of 34.370–34.724 A across all test conditions. This confirms that airflow has little effect on the current magnitude. Low pressure combined with high wind stretches the arc, changes the arc shape, increases the spatial shift of the temperature field, and reduces arc stability. At 60795 Pa and 4 m·s⁻¹, the peak arc temperature drops from 30752.78 K (with no wind) to 22986.32 K, while peripheral points decrease by up to 85.78%. The core temperature drops by only 0.56%, showing that the arc core is dominated by Joule heating and resists airflow disturbances. Further analysis shows that wind plays a larger role than pressure in shaping the temperature field and energy release. At 101325 Pa, arc energy decreases by approximately 0.34% from 58751 J at 2 m·s⁻¹ to 58549 J at 4 m·s⁻¹. This suggests that stronger airflow cools the arc and weakens its sustainability. Pressure has a smaller, stabilizing effect. Higher pressure slightly improves the spatial shift and compactness of the temperature field. The temperature integral, which measures cumulative heat over time, follows the same trend as the average temperature. This supports the idea that wind effects vary across different spatial regions. The peripheral region cools the most: at 60795 Pa, the temperature integral there drops by approximately 44% when wind speed increases from 2 m·s⁻¹ to 4 m·s⁻¹. These results provide a better understanding of series arc faults under complex environments. They also form a basis for improving arc fault detection systems and preventing building electrical fires. The numbers we report, such as the 7.1% and 85.78% voltage and temperature drop at the periphery, respectively, can serve as useful benchmarks for model validation. They also show why airflow should be a key consideration when designing detection algorithms for ventilated or outdoor settings.