Book 29, Question 85
Why do plants need less water on cloudy days?
Sun and wind make water evaporate quickly from soil and leaves.
On cloudy, cool, or still days, evaporation slows down and plants lose less water. Soil stays moist longer. That means you may not need to water as often. Checking the soil first is better than watering by habit. Rain, of course, does the job for free.