From March to May 2026, Thailand’s main rice-producing areas were in a transitional period between the harvest of the dry-season crop and land preparation for the main wet-season crop. National precipitation totaled 202.8 mm, 20.1% below the 15-year average. Mean air temperature was 29.3°C (slightly above average by 0.2°C), but extreme heat of 40–43°C occurred in the North and the upper Central region, affecting rice growth. Photosynthetically active radiation (PAR) was 4.5% below average, constraining potential cumulative biomass (−13.3%). The cropland planting ratio remained at 79.1% (close to normal), the maximum Vegetation Condition Index (VCIx) reached 0.83, and the Crop Production Situation Index was 1.02 (slightly above normal). The agricultural drought area mitigation index was −94.5%, indicating relatively strong agricultural resilience in the main producing zones.

Changes in area and crop condition: In 2026, Thailand’s planted area of second-season rice is estimated at 1,746.1 thousand hectares, a 7.7% decrease from 2025 (1,891.7 thousand hectares), mainly constrained by below-normal reservoir storage and drought risk outside irrigated areas. However, yield is projected to increase to 4,298.7 kg/ha (+11.0%), and total production is forecast at 7.506 million tons (+2.5%). The area reduction is partly offset by higher yield (Figure 2.24).

Crop condition signals indicate that NDVI was close to the long-term average in March–April, then showed a marked drop in early May due to large-scale rice harvesting, followed by a rapid rebound in late May with monsoon rainfall (about 80 mm per dekad) and irrigated replanting. The Central Lowlands (where the agro-ecological zone signal is particularly representative) recorded the smallest precipitation deficit (−17.2%), a cropland planting ratio of 81.6%, and a peak VCIx of 0.84. The “down-then-up” V-shaped NDVI trajectory in May mainly reflects harvest–replant management timing effects rather than persistent stress.

Overall, national rice conditions during this period were broadly normal. Dry-season rice harvesting was not significantly disrupted, and early establishment conditions for the main-season crop improved with the monsoon onset in mid-to-late May. However, under a developing El Niño background, attention should be paid to potential water-stress risks for rainfed main-season rice outside irrigated areas in June–July.

Figure 2.24. Spatial Distribution of Thailand's Second-Season Rice Yield in 2026