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