Al Martinez has a pre-dawn essay in today's LA Times that speaks to the stillness of that time of day. Sorry -- I know this is behind a registration wall, but registration is free.
I love the way the air feels just before the sun rises. Martinez got the feel of the change in air and light right. His first two paragraphs on the Greek goddess of the dawn, Eos (Aurora to the Romans) sounds like it was written for one of my two Greek Mythologies courses. I loved this, "By any name she brings tranquillity to the hesitant moment between night and morning -- an affirmation of renewal, a second chance for a new decision, a time not to be afraid anymore."