You can still plant spuds, but you won't get as many as if you'd planted earlier. If you've got a good sheltered spot, and don't suffer too much from slugs etc you'll have a better chance. You might be better off thinking about planting other things that you will get a lot from:
French beans, courgettes/marrows, autumn carrots and if you want small ones quickly early carrots, winter cabbages, purple sprouting broccoli, leek, lettuce, spring onions, late peas.
Bets of luck.