What are these brown spots? I first noticed it on the oregano, then it spread to the rest of the herbs. It has been very wet here this summer, with not very much sun.
It looks like a fungal infection on the leaves, which would fit with the wet weather. There's very little that can be done, you can cut back the plants if you want and make sure you clean and disinfect anytools you use. i think you can gat chemical products to help but i havnet really used them before. it could also be where raindrops have been on the leaves and acted as lenses for the sunlight and scorched the leaf underneath.
I know it may look like a fungal disease, but this is the damage caused by the 4 lined plant bug (Poecilocapus lineatus ). They stick their mouthparts in the leaf and suck out the juice....move over a bit and do it again, which causes concentrated necrotic areas. Google this bug and compare the damage with your plant. Ian