Hah, we're looking at 103F / 40C tomorrow (with up to 90% humidity). So yeah, the summer weather can be pretty brutal. Spring and fall can be nice but unpredictable.
Eureka Springs is great for tourism. You could also go to NWA as they have had a lot of growth there and a lot of folks like to visit Crystal Bridges. Do not go to Harrison, that place is not welcoming is really the heel of Arkansas. If you like the outdoors and camping there are tons of places to go such as Petite Jean, Devils Den, Mount Magazine, etc. There is also the Crater of Diamonds if you want to try and dig for diamonds.
In a small town of Gravette, AR there is a little coffee shop called Grumpys Coffee with some groovy fucking art, and it’s run by a Vietnam vet. I’ve thought about traveling to Arkansas just for some Grumpys coffee. Do it if you can