Ответ:

The clearest picture clues give these answers:

  1. January — fireworks
  2. February — hearts
  3. March — kite
  4. April — flowers
  5. May — beach scene
  6. June — child with a flag
  7. July — umbrella
  8. October — pumpkin
  9. November — candles
  10. December — Christmas tree
  11. September — autumn scene
  12. January — snowman

Some pictures can match more than one month, so the exact intended answers for the beach, umbrella, candles, autumn scene, and snowman are not fully certain from the image.