Midday sun, especially in Indian summers, is harsh. If you water plants at that time, a lot of the moisture evaporates quickly from the soil surface and leaves. The pots heat up, and roots feel stressed. Sometimes water drops on leaves can even behave like tiny lenses and scorch them.
Early morning or late evening, temperature softer hota hai. Water gets time to soak into the soil properly and reach the roots before the sun starts pulling it back out. Plants drink more peacefully, and you don’t have to water as often.
Morning watering also helps leaves dry out slowly through the day, which is good for avoiding fungal issues. Evening watering is convenient for many people returning from work. Either way, it’s kinder than blasting thirsty plants in the hottest hours.