UTCC forecasts 12.3bn-baht flood losses for September 25–29

Thanavath Phonvichai, president of the University of the Thai Chamber of Commerce (UTCC), estimates that flooding could cause 12.283 billion baht in economic losses over the five days from September 25–29, 2026. The assessment covers Bangkok and 26 other provinces across the Central, Eastern, Northern and Northeastern regions.

Thanavath, who also chairs the advisory board of UTCC’s Center for Economic and Business Forecasting, put the base-case losses at the equivalent of 0.066% of annual gross domestic product (GDP). The five-day forecast ranges from 5.896 billion to 20.635 billion baht, or 0.03–0.11% of annual GDP, depending on the extent of flooding and how long economic activity is disrupted.

The centre’s estimate excludes damage to property, including homes, vehicles and inventories, as well as agricultural output. Those losses will require surveys after floodwaters recede.

UTCC’s forecasting centre expects conditions to ease within about a week but will reassess the economic losses if flooding lasts longer than anticipated.

Bangkok accounts for 57% of projected flood losses

Bangkok faces estimated losses of 7.014 billion baht, accounting for 57% of the total in UTCC’s base case. As Thailand’s economic centre, the capital relies heavily on trade and services that depend on consumers and workers being able to travel.

Flooding in Bangkok has been concentrated in eastern areas, while much of the financial sector and office-based workforce can continue working from home, limiting some disruption.

Four provinces surrounding Bangkok face combined losses of about 1.839 billion baht, with Samut Prakan the worst affected, according to the assessment.

The Eastern region’s losses are estimated at 2.976 billion baht, including 2.101 billion baht in Chon Buri. Flooding reached Chon Buri before other areas, while its reliance on tourism, retail and port logistics makes its economy particularly vulnerable to travel disruption.

Thanavath said the impact on other industrial areas within the Eastern Economic Corridor remained limited because flooding was localised. No industrial estate in the corridor had been reported as having to suspend production.

Losses from disrupted economic activity in the Central, Northern and Northeastern regions were also assessed as relatively limited over the five-day period.

Flooding disrupts spending, tourism and deliveries

Consumption, tourism and urban services have suffered the greatest disruption, according to UTCC’s assessment. Flooding has reduced spending at shopping centres, retail outlets, restaurants and petrol stations, while preventing some workers from travelling.

The assessment also identified lost working days associated with two special holidays for government offices in Bangkok, Nonthaburi, Pathum Thani and Samut Prakan. Together, those areas account for nearly half of Thailand’s economy.

Tourism businesses in Pattaya and other destinations in Chon Buri have been affected by standing water, prompting some visitors to cancel or postpone trips. Hotels, restaurants and related services have consequently lost revenue, with much of the lost income, particularly for daily wage workers and small operators, unlikely to be fully recovered.

Flooded main roads have also disrupted logistics and deliveries to retail branches in some areas. Manufacturers have been affected mainly through difficulties transporting workers and raw materials rather than direct damage to factories, distinguishing the situation from the major floods of 2011, the assessment noted.

Vegetable prices rise ahead of October festival

Fresh vegetable prices, particularly those of tender leafy vegetables, have begun to rise, Thanavath said. Prices will need monitoring through the Vegetarian Festival on October 10–18, 2026, although UTCC’s forecasting centre expects the overall inflation impact to remain limited and temporary.

Agricultural risks are concentrated in the Chao Phraya basin, including Chai Nat, Sing Buri, Suphan Buri and Phra Nakhon Si Ayutthaya. Water levels are continuing to rise as wet-season rice approaches harvest, leaving crop losses to be assessed through field surveys after the water recedes.

Prolonged floods could weigh on second-half growth

At the currently estimated scale, the floods are not expected to change the direction of Thailand’s economy for the full year, according to UTCC’s assessment. However, the disruption will add pressure to growth in the second half, particularly if flooding in the Chao Phraya basin continues into the fourth quarter.

“The centre estimates base-case losses of about 12.283 billion baht, equivalent to roughly 0.06% of annual GDP or about 0.26% of GDP in the third quarter of 2026. This comes as Thailand’s economy is slowing, with GDP growth easing to 1.9% in the second quarter from 2.8% in the first,” Thanavath said.

UTCC’s forecasting centre called for urgent government action in three areas:

- Rapid, targeted relief, particularly for informal workers and small business operators.
- Debt repayment moratoriums or recovery loans for affected businesses.
- Water management in the Chao Phraya basin to reduce damage to agriculture and industrial estates.

The centre also urged the government to monitor the prices and availability of essential goods through the Vegetarian Festival and accelerate investment in upgrading Bangkok’s drainage system.