PIKIRAN RAKYAT - The island of Java has been cold lately. In some areas, the air temperature can reach 15-16 degrees Celsius in the morning and 18-19 degrees Celsius at night. Based on information from the Meteorology, Climatology, and Geophysics Agency (BMKG), the cold temperature is related to the dominant wind and cloud cover in the Indonesian sky.

BMKG explained that the Indonesian region, especially in the southern part, is still in the dry season. Sunny weather also dominated almost all of Java, Bali, Nusa Tenggara, southern Sumatra, southern Kalimantan, and southern Sulawesi.

The clear sky was caused by the dominant wind from the east which brought dry and cold air masses from the Australian mainland to Indonesia so that it did not support cloud growth. This then has an impact on the lack of cloud cover to make the temperature cold.

"The lack of cloud cover at night causes heat radiation from the earth's surface to radiate into the atmosphere without any obstacles, resulting in a significant decrease in temperature. In addition, calm winds at night inhibit air mixing, so cold air is trapped on the earth's surface," he said," said a BMKG statement on Instagram @infobmkg, quoted on Tuesday, July 16, 2024.

According to BMKG, highlands or mountains will feel cooler temperatures, "Because of the lower air pressure and humidity. This cold condition is a common phenomenon that occurs in Indonesia during the dry season."

BMKG issued an early weather warning for several regions in July 16-22, 2024. Here are the details:

Potential for moderate to heavy rain that can be accompanied by lightning and strong winds: Aceh, North Sumatra, West Sumatra, Riau Islands, Jambi, Bengkulu, Central Kalimantan, North Kalimantan, North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, South Sulawesi, North Maluku, Maluku, Southwest Papua, West Papua, Central Papua, Mountainous Papua, and Papua Potential impacts of heavy rain hazards in the alert category: North Sulawesi, Central Sulawesi, South Sulawesi, Central Papua, Mountainous Papua, and South Papua Potential for strong winds: Banten, West Java, East Java, Bali, NTB, NTT, West Sulawesi, South Sulawesi, North Sulawesi, North Maluku, Maluku, Southwest Papua, West Papua, and Central Papua

Ilustrasi cold temperature in Bandung. PRFM News.

Even though it is still in the dry season, the temperature in some parts of Java feels colder than usual. This phenomenon is known as bediding (Javanese: bedhidhing), a term to refer to a noticeable change in temperature, especially during the dry season, which often occurs at the peak of the dry season. The phenomenon of bediding makes the air temperature at night to morning feel cold, even the temperature during the day is also lower than usual.

Not only in Java Island, this phenomenon also has the potential to be felt in Bali, East Nusa Tenggara (NTT), and West Nusa Tenggara (NTB).

Bediding is a climatological phenomenon that often occurs in regions south of the equator, such as southern Java, Bali, NTT, and NTB. According to information from the South Sumatra Climatology Station BMKG, scientifically, the phenomenon occurs due to the process of releasing heat from the earth's surface to the atmosphere.

During the dry season, cloud cover decreases and rainfall is low, so the air humidity decreases. This causes water vapor near the earth's surface to be few. With the sky clear of clouds, the heat radiation that the earth releases is unobstructed and goes directly to the outer atmosphere, making the air on the surface feel colder.

The phenomenon of bediding usually occurs during the peak of the dry season, which is between July and September. During this period, the dry, cold Australian monsoon winds blow through Indonesian territory, bringing cold air from Australia which is experiencing winter.

Furthermore, the position of the Sun, which is at the farthest point from Earth in the revolution cycle, also contributes to the decrease in temperature, although the effect is not very significant compared to other atmospheric factors.

In southern regions of Indonesia such as southern Java, Bali, NTT, and NTB, the air temperature during the day also tends to be lower than in other months. Although the sun shines brightly without the obstruction of clouds, the cold air from the Australian monsoon stream is more dominant in lowering the air temperature during the day.

Air temperatures will return to normal as the dry season ends between July and September. After that, the weather will return to a warmer temperature pattern as usual.

Description: Indonesia's cold temperatures, particularly in the southern regions during the dry season, are a result of reduced cloud cover and cold air masses from Australia. This phenomenon, known as bediding, is most noticeable between July and September. Understanding these atmospheric conditions highlights the intricate interplay between regional weather patterns and global climatic influences.*** (Politeknik Negeri Bandung/Sintia Yuliana)