You'll want to think about what kind of promotion you can run for the end of summer (winter in southern hemisphere).
It's still several weeks away but if you start thinking now, you should have a few good ideas to pick from in July.
Come up with a promotion idea and then create marketing assets you can reuse. Assets like emails, social media messages, seasonal graphic templates, etc.
This season comes back every year so it makes sense to recognize the change and have a kit ready to make your marketing easier.
You can use the Cohort Report in Repeat Customer Insights to see how customers from those months in last year performed (e.g. how many one-time buyers vs repeat, total lifetime revenue, etc). That can give you some targets to aim for.
Market to your customer's timing
Figure out how long customers wait in-between purchases and you have a key component for your marketing timing. This is the basis of the Average Latency metric and Order Sequence Report in Repeat Customer Insights.