Taiwan is set to receive its first autumn northeast monsoon tomorrow. Early morning temperatures in some areas could drop to 17 degrees Celsius. The spell of clear skies is wrapping up. The opening cold air mass of autumn is arriving. It will bring a three-day stretch of cooling and rain across Taiwan. The forecast office says skies should clear later. Taipei recorded its third chilliest September day in a century recently. The monsoon heralds cooler weather ahead for the island.