What Is a Heatwave? Characteristics, Causes, and Is It Occurring in Indonesia?
A heatwave is currently affecting several European countries, with temperatures far above normal triggering various disruptions, from forest fires to increased health risks for the public. In Indonesia, hot weather conditions are also beginning to be felt in several regions ahead of the peak of the dry season. This has raised the question of whether Indonesia is also experiencing a heatwave like the one in Europe. Here is the explanation.
Referring to the World Meteorological Organization (WMO), a heatwave is a period of weather with temperatures significantly higher than normal conditions in a region, lasting for several consecutive days. This phenomenon can occur on land as well as in urban areas that have an urban heat island effect. Meanwhile, the National Oceanic and Atmospheric Administration (NOAA) explains that there is no single temperature threshold that applies to all countries. A heatwave is determined based on temperatures that are much higher than the average for a specific area over a certain period and lasts for at least two to three days.
According to the WMO, heatwaves generally occur when a high-pressure air system persists over an area for an extended period. This condition traps hot air near the earth’s surface, causing temperatures to rise continuously during the day and remain high at night. Climate change due to global warming has also increased the frequency, duration, and intensity of heatwaves in various parts of the world. The World Meteorological Organization states that extreme heat events are now occurring more frequently than in previous decades.
Referring to a press release from the Meteorology, Climatology, and Geophysics Agency (BMKG), the hot temperatures occurring in Indonesia cannot be directly classified as a heatwave. The BMKG asserts that Indonesia is located in a tropical region with relatively stable temperature characteristics throughout the year, making it different from subtropical or four-season countries. According to the BMKG, heatwaves typically occur in mid- to high-latitude regions that experience seasonal changes. Such phenomena are marked by a temperature rise that far exceeds the climatological average for several consecutive days, characteristics not found in Indonesia.
The BMKG explains that the hot air temperatures felt in Indonesia are more influenced by several factors, such as the apparent position of the sun, reduced cloud cover allowing for maximum solar radiation, and atmospheric conditions that support an increase in surface temperatures. During the dry season, clear weather also makes daytime air temperatures feel more intense.
Although it is not a heatwave, the hot weather still needs to be anticipated as it can increase the risk of dehydration and other health problems. Referring to recommendations from UNICEF and appeals from the BMKG, here are several steps that can be taken: drink sufficient water even if not feeling thirsty; limit strenuous outdoor activities during the day; wear thin, loose, and light-coloured clothing; wear a hat or use an umbrella when active under the sun; use sunscreen to protect the skin from ultraviolet exposure; ensure rooms have good air circulation; and pay attention to the condition of vulnerable groups, such as children, the elderly, and pregnant women. The BMKG previously forecast that the peak of the dry season in most parts of Indonesia will take place from July to September 2026. During this period, the public is urged to maintain their physical condition and follow official information from the BMKG.