By Why Does Frost Form in Atok, Benguet, Even During El Niño?
The first signs of frost, locally known as andap, have appeared in Paoay, Atok, Benguet, despite the Philippines experiencing a very strong El Niño.
On the morning of November 5, 2026, a thin layer of frost covered flowers and plants at Haight’s Place in Atok. The early appearance surprised residents, as frost is more commonly observed during the colder months of December, January, and February.
But how exactly does frost form? And why is it possible even when El Niño is bringing warmer-than-usual conditions to much of the country?
What Is Frost and How Does It Form?
Frost is a thin layer of ice crystals that develops on surfaces such as leaves, grass, flowers, and soil when conditions become cold enough.
It forms when the temperature of a surface drops to 0°C or below and there is enough moisture in the surrounding air.
Under suitable conditions, water vapor in the air changes directly into tiny ice crystals without first becoming liquid water.
Frost is particularly likely to develop during nights with clear skies and little wind.
Here’s what happens:
- The ground loses heat overnight. After sunset, the ground and plants gradually release the heat they absorbed during the day.
- Clear skies allow faster cooling. Without thick clouds trapping some of the outgoing heat, surfaces cool more quickly.
- Calm winds help cold air settle. With little wind to mix warmer and colder air, temperatures near the ground can become especially low.
- Moisture turns into ice crystals. When surfaces reach freezing temperatures and enough moisture is present, frost can form.
This explains why frost is usually most noticeable just before sunrise, when temperatures are often at their lowest.
Why Is Atok Prone to Frost?
Atok is one of the high-elevation municipalities of Benguet, making it naturally cooler than many lowland areas of the Philippines.
As elevation increases, air temperatures generally decrease. This allows mountainous communities such as Atok to experience much colder conditions, particularly when the Northeast Monsoon, locally known as Amihan, brings cooler air across Northern Luzon.
Local terrain also matters. Cold air can collect in sheltered areas, allowing some farms to experience colder conditions than nearby locations.
These factors make parts of Atok especially susceptible to frost during the Amihan season.
Can Frost Form Even When the Temperature Is Above 0°C?
Yes, and this is one of the most interesting things about frost.
Weather stations generally measure air temperature above the ground. However, leaves, grass, and other exposed surfaces can become considerably colder than the surrounding air.
For example, a weather station may record an air temperature above freezing while a nearby leaf has already cooled to 0°C or below.
This is why frost can sometimes develop even when the reported air temperature is several degrees above freezing.
The important factor is the temperature of the surface where frost forms, not simply the air temperature reported by a weather station.
Why Is Frost Still Possible During El Niño?
El Niño is a climate phenomenon associated with unusually warm ocean temperatures in the central and eastern tropical Pacific.
In the Philippines, it often increases the likelihood of below-normal rainfall, dry spells, drought, and warmer-than-average temperatures.
On November 4, 2026, PAGASA announced that a very strong El Niño was present in the tropical Pacific and could persist until the first half of 2027.
However, El Niño does not mean that every location in the Philippines will remain warm at all times.
El Niño influences broader climate patterns, while frost depends on specific weather conditions in a particular location.
Even during a warmer-than-average season, high-elevation areas can experience sufficiently cold nights for frost to develop.
The Amihan can also continue bringing cool air into Northern Luzon despite the presence of El Niño.
Although El Niño may influence the frequency and intensity of cold weather events, it does not eliminate the possibility of frost in the Cordillera.
Is Frost Good or Bad for Farmers?
While frost-covered flowers and plants can create beautiful scenery, frost is not always welcome in farming communities.
Benguet is an important producer of highland vegetables and other agricultural products, many of which are sensitive to extreme cold.
When freezing conditions become severe enough, ice formation in plant tissues can damage cells, resulting in wilted leaves, discoloration, and reduced crop quality.
Young plants and tender crops are particularly vulnerable.
However, not every frost event results in serious agricultural damage.
A thin layer of frost that disappears quickly after sunrise may cause little or no harm, depending on the crop and how cold the plant tissues become.
During the November 5 frost observation at Haight’s Place, no damage to the flowers had been reported at the time of the initial assessment.
Recognizing the risks posed by frost, DOST-PAGASA and the Provincial Government of Benguet are working on a frost-risk assessment initiative to help farming communities better prepare for these events.
Will There Be More Frost in Atok in the Coming Months?
Frost in Benguet is generally associated with the colder months, particularly January and February, when the effects of Amihan can become more pronounced.
However, its occurrence depends on the actual weather conditions during individual nights.
The ongoing El Niño may influence the 2026–2027 Amihan season, but additional frost events remain possible. Their timing and intensity cannot be determined from El Niño conditions alone.
For residents and farmers in Benguet, monitoring local temperatures and weather advisories remains important as the colder months approach.
The arrival of frost in Atok is a reminder that even during a very strong El Niño, the highlands of the Cordillera can still experience freezing conditions at ground level.
And while the delicate ice crystals may be a fascinating sight for visitors, they also remind us of the challenges faced by the farmers who cultivate these mountain landscapes.
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