From April to July, the main rice and maize crops were sown, and the harvest of the second rice was completed before June. According to the agroclimatic indicators, Thailand experienced drier and hotter than usual weather in this monitoring period with below-average rainfall (RAIN -6%), above-average temperature (TEMP +1°C), as well as increased sunshine (RADPAR +6%). All these indicators led to average biomass (BIOMSS -2%). The proportion of irrigated cropland in Thailand is 22.5%, and therefore, regular rainfall is vital to sustain crop growth.

The NDVI development graph shows that crop conditions remained noticeably below-average over the entire monitoring period. This was mainly due to a combination of factors: a period of hot and dry weather preceding late-May, followed by flooding, resulting in an overall deviation in crop conditions. Subsequently, crop conditions briefly improved but remained below-average due to temperatures and rainfall approaching normal levels. According to the NDVI departure clustering map, 51.1% of cropland exhibited a slight above-average trend after June, while it remained below-average during April to June, primarily in eastern and western areas. Around 32.4% of the cropped area, primarily located in central, northern, and southern parts, consistently remained below-average conditions, but a slight upward trend emerged after late-May, which reversed in early-July. That could be probably due to the flooding in its northern, eastern, and southern regions on July 3, 2023. The flooding was triggered by the prevailing southwest monsoon situation. About 8.3% of cropland stayed below-average but experienced a sharp drop in July, presumably due to cloud cover in the satellite images. This condition was widespread over most of Thailand, with a concentration in the central and southern parts. For the remaining 8.2% areas in the center of Thailand, a sharp decline was observed in June, and then approached near-average by the end of this monitoring period.

At the national level, almost all arable land was cropped during the season (CALF +99%). VCIx values were around 0.85. The Crop Production Index (CPI) in Thailand is 0.98, which is significantly lower than 1.15 during the same period in previous years. Nevertheless, CropWatch estimates that the crop conditions were below, but close to average, since rainfall has reached average levels starting in late May.

Regional analysis

The regional analysis below focuses on the major agro-ecological zones of Thailand, which are mostly defined by the rice cultivation typology. Agro-ecological zones include Central double and triple-cropped rice lowlands (187), the South-eastern horticulture area (188), the Western and southern hill areas (189), and the Single-cropped rice north-eastern region (190). 

Compared to the 15YA, the Central double and triple-cropped rice lowlands experienced hot and rainy conditions. Radiation (RADPAR +8%) was significantly above average, accompanied by higher temperature (TEMP +1.0°C) and rainfall (RAIN +10%). These conditions led to an above-average estimate for BIOMSS (BIOMSS +3%). The NDVI development graph indicates that crop conditions remained below the five-year average throughout the monitoring period. There was a significant decline in early July due to the impact of flooding. Subsequently, the gradual recovery was facilitated by the replenishing effect of rainfall. VCIx was 0.81. Overall, crop conditions were close to average.

Indicators for the Southeastern horticulture area show that temperature (TEMP +0.7°C) and radiation (RADPAR +3%) were above-average accompanied by lower rainfall (RAIN -6%). This led to a below-average estimate for BIOMSS (BIOMSS -6%). According to the NDVI development graph, the crop conditions were below average during this monitoring period. The VCIx was at 0.87. All in all, the conditions were unfavorable.

Agroclimatic indicators show that the conditions in the Western and Southern Hills were slightly below average: radiation (RADPAR +5%) and temperature (TEMP +0.9°C) were above average, while the rainfall (RAIN, -15%) was below average. These weather conditions led to a 4% decrease in biomass (BIOMSS -4%). According to the NDVI development graph, the crop conditions were below average during the whole monitoring period. The VCIx value was 0.87. Crop conditions are assessed as close to average.

In the Single-cropped rice north-eastern region, the rainfall (RAIN, +1%), radiation (RADPAR +6%) and temperature (TEMP +1.2°C) were all above average. All these agroclimatic indicators led to an increase in potential biomass (BIOMSS +1%). According to the NDVI development graph, the crop conditions were close to average in July, but prior to that, they consistently remained significantly below-average. Considering the moderate VCIx value of 0.85, the crop conditions were close to average.

Figure 3.40 Thailand's crop condition, crop calendar from April-July 2023

(a) Crop phenology map of major crops

(b) Crop condition development graph based on NDVI (c) Maximum VCI

(d) Spatial distribution of NDVI profiles (e) NDVI profiles

(f) Rainfall profile (g) Temperature profile 

(h) Crop condition development graph based on NDVI in the double and triple-cropped rice lowlands (left) and single-cropped rice North-eastern region (right)

(i)Crop condition development graph based on NDVI in the South-eastern horticulture area (left) and Western and southern hill areas (right)

Table 3.70 Thailand's agroclimatic indicators by sub-national regions, current season’s values and departure from 15YA, April - July 2023

Table 3.71 Thailand's agronomic indicators by sub-national regions, current season’s values and departure from 5YA, April - July 2023