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.
PC: Leslie F. Halleck
Plants are adapted to cooler nights in their outdoor environment, so they will perform better with temperature changes that mimic their natural habitat.