Thailand has three seasons:
Ruedu Nau, the "cold" season from November to February/March with day temperatures of up to 34 degrees and noticeable cooler at night. Around the turn of the year, temperatures can drop to 25 degrees during the day and below 10 degrees at night. A warm jacket and socks can be pleasant.
Ruedu Ron, the hot time from March to early June: Temperatures during the day rise to 36-40 degrees, nights stay very warm. In this time - from 12th to 15th April is Songkran, the biggest Thai festival, Thai New Year/water festival with the long Thai holidays.
The country takes on a yellow colour. While many people in Europe still have the privilege to discuss or even question climate change, this has become a bitter reality here. In Ruedu Ron 2014 we counted 6 days with more than 40 degrees, in the same period 2015 we counted 31 days with more than 40 degrees!
Ruedu Fon, the rainy season from June to October. Rain showers alternate with sunshine, masses of water fall torrentially from the sky, storms sweep over the land, which presents itself in rich green. We have no flood problems, the water drains off. That it rains for days and days is rather rare. This season is the time of fruits, but the garden often stands still because of to much water.
Thailand is basically a tropical hot country. In Isaan we have a continental climate with often big contrasts. A pleasant breeze is not rare. We recommend light cotton clothing, open shoes, closed shoes for hiking, sun protection (here very expensive!), in winter a warm jacket and socks. For temple visits arm and leg covering clothing. In the cold season, our house keeps the warmth of the day, so the temperatures never fall below 25 degrees, even at night.