The summer is coming and each day makegets a little more heathotter.

I take the Barcelona's subway and buses every day, but from a some days ago,recently they started to set the air- condictionaty is on, and it is set in aer to a really low temperature.

Some wagons aretimes it feels like a fridge, and when you are inside, you can catch a cold and start to sneeze.

wagons is a little weird in English. Maybe carts? Or just leave it out since subway and buses were mentioned in the previous sentence.

Usually I wear onlyonly wear a T-shirt, but today when I left home, I cabrought a jacket that I willo wear only ion the urbanpublic transport.

The Temperature in thePublic Transport

The summer is coming and each day makeis getting a little more heathotter.

I take the Barcelona's subway and buses every day, but from a somesince a few days ago now, the air- condictionaty ising has been on, and it is set into a low temperature.

"a some" isn't grammatical, usually if we are to use some, we would just leave it on its own "some pigs crossed" "some days I'm sad" "there's something wrong"

Some wagoncarriages are like a fridge, and when you are inside, you can catch a cold and start to sneeze.

We use "wagon" when referring to a carriage which transports cargo (such as coal, material, boxes etc.)
A carriage is more likely to be associated with passengers (you can also use 'coach' which I think is a more American expression)

Usually I wear onlyonly wear a T-shirt, but today when I left home, I caughgot a jacket that I will wear only ion the urbanpublic transport.