in 2011 For long-time Bangkok residents, yesterday's weather was the strangest in memory.
This is the beginning of the hot season but temperatures were more then 10 degrees below normal. With a brisk wind blowing, it was very much cold season weather.
What's going on?
One popular theory going around yesterday was that the sudden weather change was somehow caused by the nuclear crisis in Japan.
Fears were real enough for the Meteorological Department to come out with a statement dismissing any connection with Japan.
The sudden drop in temperature has nothing to do with the nuclear crisis in Japan as many people fear, the department says.
The abrupt change from more than 30C to 17-19C since Wednesday was caused by an intense high pressure system from China that covered Thailand, said director-general Torsak Wanitkhachorn.
The department forecasts warmer weather today. The mercury will continue to rise until a new cold spell arrives on Tuesday.
The new bout of cold weather will also be a result of high pressure from China but the drop in temperature may not be as sharp. Likewise, the next cold spell will come with rainfall but the amount will be considerably less than the current pattern.
The department yesterday reported the lowest range of temperatures at 16-18C and the highest at 26-28C, compared with a low of 25-26C and a high of 33-34C on Monday.
It urged members of the public not to panic over rumours that the colder weather was a result of the radiation crisis triggered by the March 11 earthquake and tsunami in Japan.
Mr Torsak said the department issued a forecast last week warning that colder weather would arrive this week.