What are your favourite summertime traditions?
What is your favourite summer vacation drink?
What are some of your favourite summer fashion trends?
One-piece or two-piece swimsuit?
Swim trunks or Speedo?
What's the craziest thing you have done on summer vacation?
Do you swim in the ocean? Are you afraid of starfish?
What are some of your favourite summer festivals?
If you could watch any musical act at a summertime festival, who would it be?
What is your favourite summertime fruit or vegetable?
How do you feel about summer's increased risk of sunburns or heat stroke?
What are some of your favourite summertime hobbies?
What is your favourite summertime book or movie?
What was your favourite outdoor performance?
What are some of your favourite summertime colours?
Do you have barbecues or parties in the summer?
What are some of your favourite summertime memories?
Do you road trip in the summer? Do you prefer a plane?
How do you feel about the increased number of outdoor activities in the summer?
What are some of your favourite summertime destinations?
What is your favourite summertime activity with friends?
How do you feel about the increased number of campers and hikers during summer?
Can you recall a situation in the summer when you has to communicate a) with your nemesis b) with a villain c) with your role model d) with a super hero e) with an emotionally charged or flat person f) with a socially awkward person or in a socially awkward situation 
What new skill/ fact/ topical insight / etc did you acquire in the summer?