I found a link on The Dollar Stretcher for pasta salads. These are great hot weather foods..
Hummus and tortilla chips/crackers/pretzels with "dipping veggies" (whatever we have on hand in the fridge or from the garden... often carrot sticks, celery, broccoli, radishes, sliced zucchini or cucumbers, etc.)
Tacos or burritos made with browned ground beef from the freezer, cooked pinto beans from the freezer, shredded cheese, chopped tomatoes and/or lettuce from the garden, some rice, maybe some sour cream or avocado if we have some. I only have to make a pot of rice in the rice cooker and reheat the beef and beans in the microwave. I might add taco seasoning to the beef or I might leave it plain, just depending. I do currently have some taco seasoned ground beef in the freezer specifically for these meals.
I've also done something similar using pork instead of beef for the tacos. I grease the inside of a crockpot with bacon grease, add a pork loin, season with 3/4 tsp salt per lb of meat, and cook on low for 10+ hours. This makes amazing carnitas/Kalua pork that works on top of a salad, in tacos, on a bun with bbq sauce and a side of cole slaw... it's quickly becoming a popular item around here.
We live in a very hot part of the country (north Texas) and our home is older with crummy insulation, so we definitely try to keep the oven off! I like to use my slow cooker a lot during the summers. It is also very convenient, since we both work full-time, to start a meal in the morning and have it ready when I get home!
Some of our summer slow cooker favorites are tacos or bbq. I just add whatever meat I want - a pork or beef roast, or boneless chicken pieces - and then top with either a bottle of bbq sauce or a can of tomatoes & some taco seasoning. (I do sometimes use more involved taco recipes). Let it cook on low all day & then shred with 2 forks & serve on tortillas or in buns. We've been doing this a lot with chicken & making taco salad bowls with lettuce. Very light, but filling, and no heating up the oven!
We also like to do easy salads with whatever grilled meat we have around - steak or chicken work nicely.
The other week I had a delicious caprese pasta salad for lunch every day. It was penne, storebought pesto, a squeeze of lemon, some cherry tomatoes, and mozzarella cheese chopped into chunks. I added in some chopped chicken for protein. Cool and refreshing!
I also like cold quinoa salads with tomatoes, cucumber, corn, avocado, and a light lemon juice/salt and pepper/olive oil vinaigrette. Maybe add some black beans for protein and parsley or cilantro for flavor. Scallions or sweet onions might be nice too.
We like doing a spin on taco night by having Greek pita night. I make a mixture of ground beef or chopped chicken sauteed with garlic, onions, oregano, cumin, and a little paprika. Then I serve it with chopped lettuce, tomatoes, cucumbers, artichoke hearts, olives - all things you can grab from your supermarket salad bar if you're lazy or in a pinch. I make a quick yogurt sauce with 3 parts plain Greek yogurt and 1 part mayo blended with a few chunks of cucumber, salt and pepper, and garlic powder. Add some mint or parsley to the sauce if you've got it. Serve with warm pita bread and a tub of storebought hummus.