Weather Anomaly, Unusual Rainfall In The Dry Season

The Photo Archives - A number of residents use umbrellas while walking on the sidewalk in front of the HI Roundabout in Jakarta, Thursday (19/12/2024). (ANTARA/Khaerul Izan)

JAKARTA - Indonesia is experiencing an unusual phenomenon, which is then referred to as the wet dry season. This phenomenon has a dual impact on the agricultural sector.

In recent weeks, a number of areas in Indonesia have experienced above normal rainfall. Whereas when it comes to the season, climatologically this June, Indonesia should have entered the dry season.

The term wet dry season is widely discussed in the midst of a situation like today. This phenomenon, said the Meteorology, Climatology and Geophysics Agency (BMKG) was caused by global warming.

Citing the BMKG page, this condition is not a prolonged rainy season, but a rainfall that still occurs during the dry season.

The wet dry season has a significant impact, especially on the agricultural sector. Head of BMKG Dwikorita Karnawati said the current phenomenon could be a blessing as well as a challenge.

"For rice farmers, this can help because irrigation water supplies are still available. But for holticulture, high humidity can be a serious problem," said Dwikorita.

Dwikorita also reminded that this year's dry season is expected to last shorter than usual, but is still accompanied by fluctuating rainfall until October 2025, especially in the southern region of Indonesia.

According to BMKG, wet dryness is a condition when it rains regularly during the dry season, or also known as a drought that is above normal.

Usually, the dry season in Indonesia is synonymous with hot weather and lack of rain. However, when it is wet, the intensity of rain is still relatively high even though the frequency is decreasing.

Wet Drought is influenced by the dynamics of the regional and global atmosphere. Some of the factors that cause it include warm sea level temperatures, steady-active monosum winds, as well as negative La Nina and Indian Ocean Dipole (IOD) phenomena.

In Indonesia alone, the dry season usually lasts from April to October. The dry season is usually marked by low rainfall, sunny skies, high temperatures, and low humidity. As a result of drought, reduced water availability, and the risk of cropping.

Meanwhile, wet dryness occurs when it rains even though the calendar has entered the dry season. As a result, humidity remains high, the weather is difficult to predict, and agricultural activities are disrupted.

In the wet dry season, holticulture plants such as chilies, onions, and rena tomatoes against pests and disease attacks during high humidity.

Therefore, BMKG encourages farmers to adjust their planting patterns and strengthen the plant mitigation system.

"We encourage holticulture farmers to prepare a good drainage system and strengthen plant protection. Do not let high rainfall even reduce production," said BMKG Chairman Dwikorita.

Meanwhile, meteorolgi expert from IPB University Sonni Setiawan said the wet dry season is not only related to monsun patterns and climate anomalies, but is also influenced by solar activity, especially sunspots or sunspots.

Scientifically, the term season is defined based on the pseudo position of the sun relative to observers on the earth's surface. When the sun is in the south of the equator or the southern hemisphere (BBS), the southern region of the earth gets heating due to more intense solar radiation," said Sonni.

Furthermore, Sonni explained how the heating of solar radiation in the southern hemisphere caused air in BBS to tend to have lower pressure compared to air pressure in BBU, so that the wind moved from BBU to BBS.

He called this a season cycle. However, Sonny revealed this from a normal pattern.

"It should be, during the dry season, rainfall decreases. But now it actually rains continuously. This is what is called wet dryness," said the lecturer at the Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences (FMIPA) IPB University.

Sonni also revealed that La Nina, known as one of the factors of the wet dry season, is currently detected in weak to moderate conditions and contributes to increasing rainfall during the dry season.

Meanwhile, the IOD, which shows that the difference in sea temperature in the Indian Ocean, is in a neutral condition. Therefore, said Sonny, the impact on this year's wet dryness is relatively small.

"Currently there are no strong indications of El Nino or La Nina, as well as the IOD. What is interesting is that the sunspot activity is repeated every 11 years and is at its peak since 2024 and is still active in 2025," he said.

Sunspots are dark spots on the surface of the sun that signal high radiation activity. When the sunspot increases, the sun emits more high energy particles such as cosmic rays. This particle can accelerate condensation in the atmosphere and increase cloud formation, thereby increasing the possibility of heavy rain.

"Sunspots also increase the potential gradient of electricity in clouds, so that rain accompanied by lightning occurs more often. This is one of the factors that makes rainfall increase, even in the dry season," said Sonni.