Mt. Washington Observatory measurements show September as a transitional month when average wind speeds rise from summer lows near 25 mph toward autumn peaks, with historical median maximum gusts around 94 mph and rare extremes tied to tropical cyclone remnants, such as the 174 mph record from Hurricane David remnants in 1979. Current late-August conditions feature moderate gusts of 30–50 mph under northwest flow, with no active tropical systems or major low-pressure developments in the past 30 days. Traders monitor National Hurricane Center outlooks and National Weather Service model runs for any late-season tropical moisture or strong extratropical cyclones that could produce hurricane-force gusts, as these drive the highest September readings; daily summit data releases and updated 48–72 hour forecasts will provide the next key signals for market movement.