Depending on how friable the soil is (seed ready), I would be sowing early varieties of carrot (sow they mature within the time you have left) and then depending on your personal crop rotation you could sow kale still, salads, beetroot, spinach. How about spring cabbages?
Or – sow a green manure crop to harness what’s left of the sunshine and cut and compost it ready to top dress in spring. I like leguminous green manures as you can leave the roots in the bed with the nitrogen they fix for free and compost the top growth.