Considering th mechanism of upward water movement in plants, the respones of plants to extremely hot conditions and the fast drying due to the heat suggest a general time of day would be best for watering outdoor plants and explain why

The best time of day to water plants is in the evening or early morning. This is because water applied during the day, particularly at noon, will be most affected by evaporation by the sun's energy before it can soak into the soil. By watering during the evening or early morning, the water has a chance to seep into the soil to allow maximum availability to the roots of plants.