This research work aimed to determine the response of ratoon lowland rice (Oryza sativa L.) to foliar application of seaweed extracts grown under high maximum temperatures. To determine the best seaweed extracts that can promote growth and produce a higher grain yield of ratoon lowland rice. Evaluate the profitability of rice ratooning as influenced by foliar application of seaweed extracts grown under high maximum temperatures. The experiment was implemented following a Randomized Complete Block Design (RCBD) with the spraying of seaweed extracts as a treatment. The different seaweed extracts used were Guso (Eucheuma dentilatum), Samo (Sargassum aquifolium), and Loci (Sargassum polycystum). Results revealed that spraying with fermented Sargassum polycystum extract achieved a higher grain yield (1.24 t ha^-1) and eventually a higher gross margin (USD 283.40) of ratoon lowland rice than unsprayed control and those plants sprayed Algafer commercial foliar fertilizer. Foliar application of seaweed extracts did not influence all parameters gathered even though higher productivity in plants applied with Sargassum polycystum and Sargassum aquifolium extracts. The real effect of foliar application might be due to the plant's exposure to high maximum temperatures that might reduce the absorption and translocation of applied nutrients into the ratoon crops. Thereby decreasing productivity but still higher compared to commercial foliar fertilizer. This study speculated that foliar application of seaweed extracts is one of the best options to alleviate the crop productivity that might experience low yield due to soil problems, although enhancing its productiveness when plants are grown under normal environmental conditions.