The Climate of Thailand

Thailand is located between 6 and 20 degrees north, and hence its southern region has an equatorial climate, with rainfall round the year, while the central and northern have a tropical monsoon climate with a marked dry and wet season. Northern Thailand is hilly with land rising up to 3000ft (1000m), while most of central and eastern Thailand consists of lowlands.

Thailand has abundant rainfall; the wet seeason is from May-Oct, when the country is affected by the southwest monsoon bringing warm, humid air and much cloud from the Indian Ocean.

The dry season is from Nov-April during the northeast monsoon, when winds blow overland from China or Indochina and the air is much drier. Rain then only occurs a few days each month in the north. However in the Kra Isthmus, the northeast monsoon winds bring more rain as they have blown from the Pacific Ocean and the Gulf of Siam.
 
In central and southern Thailand, temperatures do not differ much from month to month; but in the north temperatures are definitely cooler during the northeast monsoon. For most of the country, the hottest months are April and May before the onset of the southwest monsoon. Sunshine amounts for the wet months June-Sep average 4-5 hours a day, and 9-10 hours for the rest of the year. Temperatures and humidity are high during the wet season, making conditions rather oppressive. However severe heat stress is rare. Conditions are fresher and usually windier during the dry season.

	Bangkok Month Rainfall(mm) Temperature (Celsius) Ave. Monthly Ave. No. of Days with 1mm Average Daily Lowest Recorded Highest Recorded Min Max Jan 9 1 21.0 32.0 11.5 35.7 Feb 30 2 23.3 32.7 14.9 36.6 Mar 29 2 24.9 33.7 15.7 37.8 Apr 65 4 26.1 34.9 19.9 40.0 May 220 13 25.6 33.1 21.1 39.5 Jun 149 12 25.4 32.7 21.7 37.7 Jul 155 13 25 32.5 22.2 37.8 Aug 197 15 24.9 32.3 21.2 37.0 Sep 344 18 24.6 32.0 21.7 36.0 Oct 242 14 24.3 31.6 18.3 35.3 Nov 48 5 23.1 31.3 14.2 35.1 Dec 10 1 20.8 28 10.5 35.2

	Phuket Month Rainfall(mm) Temperature (Celsius) Ave. Monthly Ave. No. of Days with 1mm Average Daily Lowest Recorded Highest Recorded Min Max Jan 30 3 23.3 31.8 18.3 34.2 Feb 21 2 23.7 32.9 18.6 36.0 Mar 49 4 24.3 33.5 20.0 36.6 Apr 122 9 24.8 33.4 20.0 37.8 May 319 19 24.5 32.0 21.0 35.5 Jun 269 17 24.5 31.6 21.0 34.7 Jul 291 17 24.2 31.2 20.5 35.0 Aug 273 17 24.4 31.2 20.4 34.4 Sep 399 21 23.9 30.7 21.1 34.2 Oct 310 20 23.8 30.9 20.5 34.4 Nov 176 13 23.8 31.0 19.7 34.0 Dec 59 6 23.7 31.2 18.4 34.2

	Songkhla Month Rainfall(mm) Temperature (Celsius) Ave. Monthly Ave. No. of Days with 1mm Average Daily Lowest Recorded Highest Recorded Min Max Jan 82 7 24.0 29.6 19.1 32.8 Feb 25 3 24.1 30.4 20.3 32.8 Mar 37 3 24.2 31.4 19.7 36.5 Apr 70 6 24.6 32.6 21.0 38.2 May 120 11 24.6 32.9 21.8 36.5 Jun 101 9 24.3 32.8 20.2 36.5 Jul 95 9 23.9 32.6 21.1 36.2 Aug 100 10 24.0 32.6 21.3 36.2 Sep 130 11 23.8 32.2 21.0 35.9 Oct 283 18 23.8 31.1 20.7 35.2 Nov 588 20 23.9 29.6 20.4 34.0 Dec 404 17 24 29.1 20.7 33.3

	Chiangmai Month Rainfall(mm) Temperature (Celsius) Ave. Monthly Ave. No. of Days with 1mm Average Daily Lowest Recorded Highest Recorded Min Max Jan 7 1 13.7 28.9 3.7 34.1 Feb 5 1 14.9 32.2 7.3 37.3 Mar 13 1 18.2 34.9 10.0 39.5 Apr 50 5 21.8 36.1 15.8 41.3 May 158 12 23.4 34.1 19.6 41.4 Jun 132 12 23.7 32.3 20.0 38.5 Jul 161 14 23.6 31.7 20.5 37.5 Aug 236 17 23.4 31.1 20.7 36.5 Sep 228 14 23.0 31.3 16.8 36.1 Oct 122 9 21.8 31.1 13.3 35.3 Nov 53 4 19.0 29.8 6.0 34.5 Dec 20 1 15.0 28.3 5.0 33.0