When to Harvest Salad Greens

Morning or night? I know if I want to harvest during day, it's best to do it before sun really hits the plants, but is it better at night or early a.m.?

or does it really matter? (my concern is pest/sun damage afterwards)

I like to harvest at the coolest time of day for green salad but to be honest I only harvest enough to meet the needs for that meal, so Maybe in your heat I'd suggest evening when it's cooler, but you know, there is nothing nicer that preparing your meal and just popping outside for a lettuce etc, washing it and eating it there and then, the taste cannot be matched in my opinion.
There are so many different types of green salad, some regrow and do so all season, others you need to cut the whole lettuce from underneath at ground level, this is also a way gardeners use to thin out there crops. you need to do what suits you AND the type of plants you grow, for the pick a few leaves and they re-grow more leaves, don't CUT the leaves as it bruises them and can let mold or other diseases in, just pull off the leaves you want for that sitting.
Good luck. WeeNel.

I can't believe I'm still picking Lettuce in December.

I can't believe I'm GROWING lettuce in December!

"liking" gymgirl's post - I actually have more seedlings that I have to put out into the garden - he have a high of 72-75 today.

The seasons and temps are all mixed up all over the world, believe me I have had Rhododendrons that have flowered 3 times this year, I have got a Clematis that flowers every spring and it has came into flower again and is lasting for weeks, I think it will be gone now as we have just had 109 mile an hour gale force storm and the remaining leaves that were clinging onto the shrubs and trees are now on the ground, we had snow, hailstones the size of marbles and a touch of sunshine for about 20 minutes, then really heavy rain washed the snow and hailstones away but it is bitter cold and very damp, someone was asking how to grow moss, well my whole lawn has been taken over this year with moss and the soil has never had the chance to dry out, the dryness will kill off the moss thankfully, one Man's weed is another mans thing of beauty eh.
Take care and good luck. WeeNel.

Sorry to hear of your dilemna WeeNel, we had a rough time with weather here too. This summer First Hurricane Irene, then a tropical storm, then 60 day's of rain through the summer, I love my French Drains.
GG that's amazing.

I always thought my dad was the best gardener ever and I still think he was as far as summer veggies are concerned but he didn't have a clue that radishs, carrots, cabbage, onions and lettuce could be planted in the fall and carried through the winter.