Tomatoes Won't Ripen? It's the Temperature!
November 27, 2018
Tomatoes are a warm-season crop that can grow at temperatures between 60°F and 80°F (15–26°C), but that doesn’t mean they will perform their finest at a constant temperature of 80°F (26°C). If you have tomato fruit on your plants but they just won’t ripen, temperatures are consistently either too cool or too hot.
Plants are adapted to cooler nights in their outdoor environment, so they will perform better with temperature changes that mimic their natural habitat.