All’s looking rosy for visitors to Thailand in December, with little rainfall, temperatures in the mid to high 20s°C and plenty of blue skies. Early mornings and evenings in the northern hills can have a slight chill in the air, but this is relative to the rest of the country and the hiking conditions are prefect. Similarly low humidity and average temperatures of 26°C in Bangkok and central Thailand are ideal for sightseeing. For the best beach weather head to the west coast around Phuket, Khao Lak and Krabi.
To get the keenest prices head over in the first 2 weeks of December before the Christmas supplements start to kick in.