121 EXTRA HEAT DAYS: Climate change is brewing trouble for Iloilo coffee

By Francis Allan L. Angelo

Iloilo – the country’s fifth-largest coffee-producing province – is experiencing 121 extra days of coffee-harming heat per year because of climate change, making it among the hardest-hit growing areas in the Philippines, according to a new analysis from Climate Central.

The province recorded an average of 186 total days annually between 2021 and 2025 when temperatures exceeded 30°C (86°F), the threshold that scientists consider extremely harmful for arabica coffee plants and suboptimal for robusta.

That means Iloilo’s coffee-growing areas spent more than half the year enduring dangerous heat, with nearly two-thirds of those extreme days directly attributable to climate change.

Iloilo produced 5,736 metric tons of coffee in 2023, according to Philippine Statistics Authority data, placing it fifth nationally.

The convergence of high production volume and severe climate-driven heat raises urgent questions about the province’s capacity to sustain its coffee output in the years ahead.

The province’s 121 climate-change-added heat days far exceed the Philippine national average of 71 extra days per year.

It also surpasses the added heat days recorded for other major coffee-producing provinces such as Maguindanao at 109, Davao del Sur at 103, Cavite at 80, Sultan Kudarat at 77, and Batangas at 75.

NATIONAL PICTURE

Nationally, the Philippines ranked sixth among 25 major coffee-growing countries for the most climate-change-driven heat days added to its growing regions.

The country experienced an average of 123 observed days of coffee-harming heat annually and 71 extra days added by climate change between 2021 and 2025. That ranking puts the Philippines ahead of larger producers like Brazil, Vietnam, and Colombia in terms of extra heat days driven by carbon pollution.

The findings are especially troubling for a country that produces all four commercially viable coffee varieties – arabica, robusta, liberica (locally known as barako), and excelsa – and was once the fourth-largest coffee exporter in the world during the 1880s.

Coffee-growing regions span the archipelago from the Cordillera highlands of Luzon to the lowlands of Mindanao.

Climate Central’s provincial-level data reveals stark variation across the country.

The provinces that saw the most extreme heat days added by carbon pollution were Misamis Occidental at 150 extra days per year, North Cotabato at 140, Southern Leyte at 137, and Leyte at 136.

These figures far exceed the national average, indicating that certain areas of the Visayas and Mindanao are bearing a vastly disproportionate share of climate-driven heat stress.

In terms of total observed days of harmful heat regardless of cause, Bohol was the hottest coffee-growing area in the country at 295 days annually — meaning coffee plants there endured temperatures above 30°C for more than 80% of the year. It was followed by Southern Leyte at 252 days, Pangasinan at 238, and Maguindanao at 234.

A few areas, however, were completely spared. Lanao del Sur, Mountain Province, and Sulu recorded zero days of coffee-harming temperatures during the five-year period, likely because of higher elevations or cooler microclimates that kept daily maximums below the 30°C threshold.

OVERLAP

When the Climate Central data is cross-referenced with the country’s top 10 coffee-producing provinces, the overlap between high production and high heat exposure is striking.

Maguindanao, the seventh-largest coffee producer at 4,269 metric tons, recorded 234 observed days of coffee-harming heat annually, with 109 of those added by climate change.

Davao del Sur, the fourth-largest producer at 7,713 metric tons, experienced 124 observed days and 103 added.

Sultan Kudarat, the top coffee province by volume at 21,442 metric tons, saw 88 observed days and 77 added.

Cavite, the country’s third-largest coffee-producing province at 8,190 metric tons and the historical home of liberica cultivation in the town of Amadeo, recorded 168 observed days of extreme heat with 80 added by climate change.

Batangas, the birthplace of Philippine coffee and the eighth-largest producer at 3,658 metric tons, experienced 176 observed days with 75 added.

The country’s remaining top 10 coffee provinces — Bukidnon at 9,042 metric tons, Davao de Oro at 4,346, Sulu at 3,563, and Basilan at 3,222 — are all in Mindanao.

Seven of the 10 largest coffee-producing provinces are concentrated on the southern island.

Notably, while Sulu appeared on the top 10 list for production, Climate Central data recorded zero coffee-harming heat days for the province – suggesting its coffee-growing areas may be shielded by elevation or other local conditions.

The data suggests that several Philippine provinces with the highest coffee output are also among those most exposed to escalating heat stress, raising questions about the long-term viability of current growing areas – particularly for heat-sensitive arabica, which requires cooler conditions than robusta.

GLOBAL TREND

The Philippine picture mirrors a global pattern. Climate Central’s analysis, published Feb. 18, found that all 25 major coffee-growing countries it studied experienced more coffee-harming heat between 2021 and 2025 because of climate change. These 25 countries account for about 97% of global coffee production.

The study defines coffee-harming heat as daily maximum temperatures exceeding 30°C — a threshold that is extremely harmful for growing arabica coffee plants and suboptimal for growing robusta varieties. Beans from these two species make up the vast majority of the global coffee supply, with arabica accounting for about 60% to 70%.

The top five coffee-producing countries – Brazil, Vietnam, Colombia, Ethiopia, and Indonesia – are responsible for roughly 75% of the world’s coffee supply. These five nations now experience coffee-harming heat for more than 144 days of the year on average. Without the influence of climate change, there would be about 57 fewer days each year with such heat.

Among the top five producers, Indonesia experienced 73 extra days of coffee-harming heat annually because of climate change, while Brazil – the world’s top coffee-growing nation, supplying 37% of global production – saw 70 extra days. Vietnam had 59 extra days, Colombia had 48, and Ethiopia had 34.

Brazil’s top coffee-growing state, Minas Gerais, experienced an extra 67 days of extreme heat each year during the period.

Across all 25 countries analyzed, the average was about 47 extra days of coffee-harming heat added annually by climate change. The countries that saw the most additional harmful heat days were El Salvador with 99, Nicaragua with 77, and Thailand with 75.

HARDER TO GROW

Coffee – one of the most popular beverages in the world, with more than 2 billion cups consumed every day – is getting harder to produce and more expensive to buy, as climate change intensifies heat across the global “bean belt.”

Arabica coffee plants are significantly more sensitive to rising temperatures than robusta varieties. Research shows that even cooler temperatures in the 25°C to 30°C (77°F to 86°F) range are suboptimal for arabica growth, making the 30°C threshold a conservative estimate of the actual climate impact on this species. Arabica is also typically farmed at higher elevations, where temperatures may be cooler than the area-weighted regional averages used in the analysis.

Changes to rainfall patterns compound the heat stress. Adequate and consistent rain is crucial for coffee plant growth, with optimal annual totals falling between 59 and 79 inches. A 2023 drought in Brazil has been linked to recent spikes in global coffee prices, which reached record highs in December 2024 and again in February 2025.

Shifting temperatures and rainfall patterns also influence the spread of pests and diseases such as coffee leaf rust and the coffee berry borer, which can reduce both the quantity and the quality of bean harvests. The Philippines has its own painful history with coffee rust — the disease devastated Batangas plantations in the late 1880s and collapsed the country’s once-thriving export industry by 1891.

If farmers are unable to adapt, climate change threatens to reduce the amount of land suitable for coffee production by up to 50% by 2050. Current coffee-growing regions may become too warm over time, especially for heat-sensitive arabica, and the optimal zones for cultivation may need to migrate to higher, cooler elevations.

ADAPTATION, RISK

While relocating to previously unsuitable areas could create new economic opportunities, the primary environmental risk is deforestation as farmers clear existing forests for new coffee fields.

Farmers are already exploring adaptation strategies. Planting a taller tree canopy that shades coffee plants can protect them from harmful heat, while also enriching the soil and providing wildlife habitats, particularly for birds. The Smithsonian’s Bird Friendly® certification program recognizes organic coffee and cocoa farmers who use such sustainable agricultural practices.

The analysis used Climate Central’s Climate Shift Index, an attribution science tool that compares observed temperature data from the ERA5 reanalysis system with estimates of temperatures that would have occurred in a world without carbon pollution. The methodology counts the number of days each year that maximum temperatures crossed the 30°C threshold solely due to the influence of carbon emissions.

Climate Central also noted that climate change is severely affecting global cocoa production, heating up West Africa’s cocoa belt with implications for chocolate supplies. Ghana experienced over 60 days of extreme heat annually between 2015 and 2024 — temperatures above 32°C (90°F), which exceed the upper limit for optimal cacao growth — while Nigeria experienced nearly 60 such days during the same period.