Objective To investigate the characteristics and stabilities of yield and quality for early- and late-season rice in South China during years with extreme rainfall, explore their relationship with meteorological factors, and provide a theoretical foundation for cultivating and breeding resilient rice varieties that are resistant to adverse conditions and have stable yields in the region.

Method Eighteen indica rice varieties were planted in both early and late seasons at the Baiyun Experimental Base of the Guangdong Academy of Agricultural Sciences. Using a randomized block design, yield and quality traits were measured and their correlations with meteorological factors were analyzed to assess the sensitivity of double season rice growth and development to these factors.

Result The yield of early-season rice showed a significant negative correlation with the diurnal temperature range and mean total radiation during the vegetative growth period, while the eating quality showed a significant positive correlation with rainfall during the reproductive growth period. The head rice rate of late-season rice showed highly significant negative correlations with daily maximum and minimum temperatures during reproductive growth, while chalky grain rate exhibited significant and highly significant positive correlations with daily maximum temperature and minimum temperature, respectively. The stability of head rice rate, chalky grain rate, and yield all correlated with temperature during the reproductive growth period. Specifically, daily maximum and minimum temperatures in the early season governed head rice yield stability, while in the late season, they influenced chalky grain rate, and the diurnal temperature range determined yield stability. This trial identified five high-yield, stable varieties suitable for both early and late seasons, i.e. ‘Liuxiangyou 908’ ‘Guangtaiyou 816’ ‘Wuyou 308’ ‘Huangguanghuazhan No.2’ and ‘Taifengyou 208’. Early-season yields ranged from 6 681.63 to 7 378.59 kg·hm⁻², while late-season yields reached 7 901.47 to 8 439.52 kg·hm⁻².

Conclusion The temperature during the reproductive period in extreme rainfall years is a key factor leading to unstable yield and quality of early- and late-season rice in South China. Hence, utilizing high-yield, stable varieties adapted to both seasons, constitutes a key strategy to achieve large-scale production stability under extreme rainfall conditions.