Frost blankets Arjuna Temple complex in Dieng once again
The frost phenomenon, locally known as bun upas, has once again blanketed the Arjuna Temple complex in Dieng Kulon Village, Banjarnegara Regency, Central Java, over recent days, coinciding with the arrival of the dry season.
Dieng Kulon Village Secretary Sabar Alfarisi said the frost began appearing over the last three days as air temperatures continued to fall during the night and early morning. “Frost started appearing in Dieng around three days ago. Its distribution is visible around the Arjuna Temple complex and several other open areas,” he said.
According to him, the natural phenomenon characteristic of Dieng’s dry season consistently attracts tourist attention, with many visitors arriving in the early hours to witness and document the formation of thin layers of ice crystals on grass and plants. “Many tourists have come to see and photograph the frost. This phenomenon always holds a special allure for visitors to Dieng,” he added.
Based on data from the Meteorology, Climatology and Geophysics Agency (BMKG), rainfall in the Dieng area recorded 0 millimetres during the 6-9 June 2026 period. “Zero millimetres of rainfall indicates the atmosphere is in a very dry condition. Additionally, the sky tends to be clear without clouds from night until morning,” he explained, noting that the absence of cloud cover allows heat stored in the earth’s surface during the day to be released maximally into the atmosphere and outer space at night, causing rapid cooling and a drastic drop in surface temperature.
Air temperature data showed Dieng’s minimum temperature reached 1.05 degrees Celsius at 1:01 a.m. local time on 9 June 2026, whilst grass or ground surface temperatures were recorded even lower at 0.60 degrees Celsius at 8:30 a.m.
He said Dieng’s topography, a basin surrounded by mountains, further reinforces the formation of frost. “Cold air from the mountain slopes descends at night and becomes trapped at the valley floor, making the temperature in that area far lower than surrounding regions,” he stated.
In light of this, he urged residents and tourists visiting Dieng to prepare warm clothing and remain vigilant of extreme cold temperatures, which are forecast to continue in the coming days, particularly during the night and early morning.