The silly season is the period lasting for a few months (starting in mid- to late summer) in the United States, the United Kingdom and Australia, typified by the emergence of frivolous news stories in the media.
This term was known by the end of the 19.th century and listed in the 2.nd edition of "Brewer's Dictionary of Phrase and Fable" and remains in use at the start of the 21.st century. The 15.th edition of Brewer's expands on the 2.nd, defining the silly season as "the part of the year when Parliament and the Law Courts are not sitting (about August and September)".
Typically, the latter half of the summer is slow in terms of newsworthy events. Newspapers as their primary means of income rely on advertisements, which rely on readers seeing them, but historically newspaper readership drops off during this time when in the UK, Parliament takes its summer recess, so that parliamentary debates and Prime Minister's Questions, which generate much news footage, do not happen.
To retain – and attract – subscribers, newspapers would print attention-grabbing headlines and articles to boost sales, often to do with minor moral panics or child abductions. Other countries have comparable periods, for example the "Sommerloch" (summer hole) in Germany and "Mätäkuun juttu" (rotten-month feature) in Finland.
Wikipedia (abridged and adapted)
In Portugal, one would tend to see this period as an absolute void.
Nothing happens (or seems not to happen), everyone heads for the very same places, newspapers and "heart"/socialite magazines "offer" whatever they can come up with to ensure a minimal amount of "readers": slippers, handbags, beach towels, "shades", skin protectors, you name it…
Even the national part of the bloggosphere seems to have been deserted. Many diligent bloggers just vanish for a while, but some of them seem not to resist that drive that takes them to a near cybercafé to have a look at what others keep on posting. I believe they read as many posts as they can, but just don't have the time or the home comfort to comment.
Living in Lisbon turns into some kind of a short staying in paradise: much less cars, much less people, and great opportunities to enjoy evening/night cultural life.
Well, it's not so bad after all…
Enjoy it lavishly if you happen to be around!