Why Does Thailand Stay Hot All Year?

Created By RISC | 4 months ago

Last modified date : 4 months ago

Thais joke that their country has 3 seasons: hot, very hot, and super hot. It's not the climate they’d prefer.​

Thailand actually has 3 seasons: summer, rainy season, and winter. So why do we always feel hot? Let's try to find why...​

When you check the air temperature, you’ll often see "feels like …." This perceived temperature is usually higher than the air temperature on the thermometer. The number is calculated with factors such as air temperature, relative humidity, wind speed, and solar radiation.​

RISC simulated the outcomes and examined the data's accuracy.​

The Meteorological Department's 2021 weather data show average maximum temperatures in the summer, rainy season, and winter of 36°C, 34°C, and 33.5°C. Foreca, an accurate weather forecast data source, said average relative humidity in summer is 73.33%RH, in the rainy season is 76%RH, and in winter is 69.5%RH. Wind speed averages 6 km/hr in summer, 4 km/hr in the rainy season, and 4.75 km/hr in winter.​

​The solar radiation value was analyzed using a simulation software tool, and a substantial radiation concentration number was discovered within one day of the summer, rainy, and winter seasons. The maximum average solar radiation was 0.41 kWh/m2, 0.25 kWh/m2, and 0.38 kWh/m2, respectively. These figures are consistent with clear skies and few clouds in winter and summer, letting the sun's rays go straight to the earth. During the rainy season, many clouds can obstruct the sun's beams.​

The data analysis revealed that ​

• Summer has the highest temperatures, wind speeds, and sun radiation. Perceived temperature is 42.7°C.​

• The rainy season has moderate temperatures and the highest relative humidity. Perceived temperature is 41°C.​

• Winter has the lowest temperatures, relative humidity, wind speed, and sun radiation. Perceived temperature is 38.4°C.​

As we can see, we frequently sense air temperatures that are higher than the thermometer reading due to factors such as relative humidity, wind speed, and sun radiation. In the summer, even with high air temperature and sun radiation values, wind not only lowers the temperature to a comfortable level but also makes us feel the temperature drop. And if we are in an atmosphere with an air temperature of 22-29°C or lower and the wind speed increases by 1 kilometer per hour (km/hr), we will feel 0.4 °C cooler.

Furthermore, having a relative humidity value higher than the comfort zone of 20-75% during the rainy season contributes to us feeling hotter and more uncomfortable. The greater relative humidity rating will make you feel even hotter because the rate of perspiration evaporation from your body reduces.​

Using simulation software in analysis allows us to clearly and reliably forecast future outcomes that have yet to occur. The results of the solar radiation simulation can also be used to improve building design and orientation, boosting comfort throughout the year and in each season.​

RISC employs a team of experts who can analyze data on the sun's orbital path using Building Information Modeling (BIM). The simulation software creates building virtual models to study the intensity of solar radiation on the surface and display accurate results based on Thailand’s weather data.

Find out more from Research & Innovation for Sustainability Center (RISC) at the RISC Well-Being Facebook Inbox or RISC LINE Official: risc_center.​

Story by Panisara Sucharitkul, Sustainable Designer, Well-Being Research Integration, RISC​

References:​
Air temperature: https://weather-and-climate.com/Bangkok-January-averages​

Sky conditions: http://164.115.28.46/thaiexen/search_detail/result/8374​

Relative humidity and wind speed: https://weather-and-climate.com/Bangkok​

The Feel Like temperature (Perceived Temperature): https://planetcalc.com/2089/​

How the wind speed makes us feel cool: https://risc.in.th/knowledge/electric-fan-saves-more-energy#:~:text=%E0%B9%82%E0%B8%94%E0%B8%A2%E0%B8%A1%E0%B8%99%E0%B8%B8%E0%B8%A9%E0%B8%A2%E0%B9%8C%E0%B8%88%E0%B8%B0%E0%B8%A3%E0%B8%B9%E0%B9%89%E0%B8%AA%E0%B8%B6%E0%B8%81%E0%B9%80%E0%B8%A2%E0%B9%87%E0%B8%99,C%20%E0%B9%80%E0%B8%A3%E0%B8%B2%E0%B8%AA%E0%B8%B2%E0%B8%A1%E0%B8%B2%E0%B8%A3%E0%B8%96%E0%B9%80%E0%B8%9B%E0%B8%B4%E0%B8%94%E0%B8%9E%E0%B8%B1%E0%B8%94%E0%B8%A5%E0%B8%A1

Relative humidity makes us feel hot:​ https://mgronline.com/science/detail/9630000049979#:~:text=%E0%B8%97%E0%B8%A7%E0%B9%88%E0%B8%B2%E0%B8%84%E0%B8%A7%E0%B8%B2%E0%B8%A1%E0%B8%8A%E0%B8%B8%E0%B9%88%E0%B8%A1%E0%B8%8A%E0%B8%B7%E0%B9%89%E0%B8%99%E0%B9%83%E0%B8%99%E0%B8%9A%E0%B8%A3%E0%B8%A3%E0%B8%A2%E0%B8%B2%E0%B8%81%E0%B8%B2%E0%B8%A8,%E0%B9%80%E0%B8%A2%E0%B9%87%E0%B8%99%E0%B8%88%E0%B8%A3%E0%B8%B4%E0%B8%87%E0%B9%86%20%E0%B9%80%E0%B8%A1%E0%B8%B7%E0%B9%88%E0%B8%AD%E0%B8%AD%E0%B8%B2%E0%B8%81%E0%B8%B2%E0%B8%A8%E0%B9%81%E0%B8%AB%E0%B9%89%E0%B8%87