Surface winds are an important factor in wildfire growth and the
decision-making process of when utility companies shut off power to
suppress fire ignitions. However, long-term trends in surface winds and
their implications for fire weather have received less attention
compared to trends in temperature, humidity, and precipitation. This
article uses the ERA5 reanalysis to calculate surface wind trends over
California during 1979--2019. We find statistically significant
increases in surface easterlies during autumn on the western slopes of
the Sierra Nevada Mountains and increases in Hazardous Wind Events of
heightened wind-related fire risk. Using the Canadian Fire Weather
Index, we also show that wildfire risk has mainly increased over the
Sierra Nevada Mountains, indicating that strengthening winds has
contributed to a growing risk of wind-driven wildfires in this region
compared to 40 years ago.