I finally found out why my basil kept dying after a chat at the Ramsey farmers market
Stopped by a little stall at the Ramsey farmers market last Saturday and got talking to a guy selling herb starts. He asked what pot my basil was in and when I said a 6 inch one, he said the roots bake in that thing by July. He told me to go up to at least 10 inches and put the pot where it only gets morning sun, not that full afternoon blast on my south railing. Moved my plant that same day and two weeks on it's actually putting out new leaves instead of going crispy. Anyone else had luck with bigger pots on a hot balcony, or do you shade yours a different way?
Basil roots actually stay cooler in light colored pots since dark ones soak up way more heat from the sun. Might be worth checking what color yours is.