In what has seemingly become an annual tradition, the date of the Steam Summer Sale has been leaked by Paypal. According to a tweet by the UK division of PayPal, the Steam Summer Sale of 2017 will begin on Thursday, June 22nd.
PayPal has preemptively announced the date for notable Steam sales in the past via email and social media and they have been very accurate. It is safe to say that the next Steam sale is right around the corner.
Thanks, PC Gamer.