This one has so far been positively sweltering, boasting afternoon temperatures in the late 20s in Rio de Janeiro and Sao Paulo at the start of the tournament.
But Manaus, where England face Italy, is another prospect entirely.
We’ve all heard about its jungle location in the heart of the Amazon, but should this really have an impact on professional footballers not fully acclimatised to the conditions?
The simple answer is, yes, of course it should.
I have been here for a morning, and have already picked up a touch of sunburn, which is no mean feat – I am an Arab, after all.
But far worse than the scorching sun and 30 degrees plus temperatures, is the sweltering, jungle humidity.
It is, quite simply, stifling.
I arrived in Manaus at 3am this morning local time, having successfully hot-footed it from the opening game in Sao Paulo to a fairly uncomfortable four-hour redeye flight. I have barely slept a wink since.
Even with air conditioning blaring through my room, the air is so heavy that it is difficult to breathe, although the anti-malarial tablets recommended for this region also have an impact.
Manaus is a decaying former industrial centre, and the decline of its rubber industry has been mirrored in its shabby, scrappy architecture and unkempt streets.
The jewel in its crown is the remarkable Teatro Amazonas (Amazon Theatre), a late 19th Century architectural masterpiece designed to showcase the then booming rubber city’s cultural power.
Manaus’ real beauty comes outside the city, in the jungles across the Amazon, home to more species of flora and fauna than anywhere else, and also home to indigenous tribes, whose descendants are more marked here than in other Brazilian cities.
But the beast is in the climate. The city is not only flanked by jungle but has patches of it peppered throughout its sprawl. The humidity is inescapable.
— Reda Maher (@Reda_Eurosport) June 13, 2014
This is not to say England will have any excuses for a poor performance tomorrow as both they and Italy will be stifled and choked in their survival of the fittest.
But it will almost certainly have an effect on the match as a spectacle. Brazil's opening win over Croatia, for example, was played in a fine evening sunset that cooled off as the match wore on.
England and Italy will draw no such benefits in the incessant, head-shrinking heat of Manaus.
Eurosport’s Reda Maher is on location in Brazil for the duration of the 2014 World Cup - follow him on Twitter @Reda_Eurosport