Whoa, I'm actually translating a song? And it's nothing to do with Vocaloids? Clearly a sign of the impending apocalypse!
I believed it was destiny, under that hot sky
We held each other so tightly it hurt and even the sea seemed to burn 
For a moment, my eyes were dazzled by the shimmering of the hot air
Counting the waves, you seemed so distant
"That too-dazzling scene was surely
An illusion," the autumn cicadas whisper to me
Are the memories that disappeared into the waves
Still alive out there, somewhere, with you?
As you left with scarcely a word
The unseasonable rain drummed on your shoulders
"Let's stay like this for-" You cut off my words
The cold sea breeze stroked your worried cheek
The setting sun cut short our footprints in the sand
Swept away bit by bit, that summer disappeared too
What have you forgotten?
The serene autumn sky is too high and far away
I visited the October beach alone
Feeling the season in the stillness of the water's surface
I stood silently, frozen, lost in thought
The sand under my thumb grates painfully even now
The people have all vanished from the shore
But summer will surely come again 
Before the cold autumn wind passes by
I return the goodbye I should have said to the waves
 I know it's literally referring to the sound of the sea (ditto for the last line of that stanza), but it just sounds odd when I try to translate it like that.
 Again, it's literally "a new season will come again", but thinking about it I realized that while I see 新しい季節 all the time in Japanese songs, it's not something one would really say in English, so. I don't know, I may have taken too many liberties with this translation.