Traditionally we are told to avoid watering on hot, sunny days at all costs, as water droplets can apparently create tiny lenses to focus the sun’s rays and burn the leaves of plants.
People who dutifully follow this horticultural gospel may avoid watering extremely thirsty, wilted plants in scorching weather due to fear of burning them.
However, in reality water droplets evaporate off far too fast for this “lens effect” to ever actually happen.
The benefits of giving severely dehydrated plants water when they need it most will outweigh any potential risk.
The only caveat here is that precisely because water evaporates off quickly on hot, sunny days, watering in the cool of the evening or morning is generally more efficient