All at once the light is tawny and the fireflies are gone and my little street smells of wood smoke. Pine, I think.The fourth real autumn of my life is settling gently around Washington, and I'm astonished all over again. I still cannot believe this happens every year.

You old-timers will please forgive the smugness, but you have no idea how extraordinary the change of seasons really is. In San Francisco, where I grew up, there are no seasons. Every six months or so the city just heaves quietly, a sleepy purebred rolling over, and the summer fog trades places with the winter rain.

It is a soothing silvery blur of a climate, briefly glorious in May and September, but it is never very hot and never very cold and the air never tastes like change.

Here the world is so different outside. I can stand on my porch and feel what is coming, a whispered warning, a chill perceived somehow inside the skin. The elm tree out front flickers gold way up high. Winter hovers in the sunshine, waiting.

In San Francisco grammar school we learned from books: Spring Brings Budding to the Barren Land. There was always a picture, sort of Grandma Moses innocent in my memory now, of a tree on a hillside. Some solid, no-nonsense kind of tree - apple, or elm. We saw the tree in its four stages: first blossoming, then full, then rust and scarlet brilliant, and then bare. The teachers urged a wider meaning on us: not just trees, they would explain. The cycle is for all of us.

We humored them, of course. We were polite. We closed up our Grandma Moses pictures and escaped into the San Francisco streets, to hedges still lush in February, to spindly eucalyptus trees that never lost their fragrance. My mother's tea rose grew full and graceful, as violently yellow at Christmas as it was in May.

I am not sure when it came to me that there was something wrong about all this. Maybe it was watching my mother, by then 20 years away from her home in Minnesota and still not quite adjusted, gazing wistfully out the window at the steady San Francisco cool. "I want snow," she would say, an edge of resentment in her voice, as though the tea rose had betrayed her.

She had a long, red Pendleton, a wool lumberjack shirt still smokemusty from camping trips in the North Woods. When I was tall enough I began borrowing it, haphazardly at first, and then on a schedule so carefully timed that I saw I was making my own season. October was for wearing the lumberjack shirt. Never mind that the San Francisco air rarely drops below 55 degrees in October, or in November either, for that matter. I needed, somehow, to label the passage of time, and if the air would not force rituals of progression on us, I would make them up myself.

The sense of past and future is what a seasonless place lacks. Memory is dimmer, presentiment more elusive. And although California is a vast, elaborate palette of a state, almost every American climate somewhere inside it borders (I knew about snow - snow was what you drove to, with skis on the back and tire chains in the trunk, and when the lift tickets were used up you drove home), we descended on the seasons at times and places of our choosing. A San Francisco kid never saw the world swell and subside at a pace of its own.

One September my best friend and I climbed onto the Coast Starlight, the night train north out of San Francisco, and went off to see about seasons. Barbara was from Newport Beach, where babies are born wearing boat shoes. She could not imagine what a real autumn felt like either, and so the two of us hung out the open space between the cars, clutching Nova Scotia guidebooks and waiting for a yellow leaf.

The first one appeared somewhere around Puget Sound, as I remember, and we just about fell off the train in delight. "Yellow leaves!" Barbara cried, mystifying the conductor. All the way across Canada, a long and crazy journey in train cars and ferry boats and cattle trucks, we marveled at the leaves like grateful immigrants, elbowing each other to point out every new tree more brilliant than the last.

In Ipswich, Mass., my aunt took us in. "The thing about autumn," she said, "is that you go for these long drives in the country and get home to find the most glorious tree standing just down the block." It was true; hers was a maple, enormous and old. We elbowed each other some more and went out to find an apple cider stand.

I went back to California to finish school and Barbara stayed in New England, sending awestruck dispatches on the changing land. "I bought an ice scraper," she wrote proudly. "And snow tires." Her car locks froze and she bought her first winter coat.

In March a desperation crept into the letters: "I want SPRING," she wailed. All I knew about spring was that the brown hills turned green and the sight of bare knees rattled everybody. I did not understand.

Now I do. I moved to Washington and I understand with the passion of a new convert what my friend was writing about. I made a religious ceremony of the purchase of my coat, a long black coat with pockets to plunge my hands in and a collar that turned up against the winds I imagined knifing over the Washington streets. On the morning of the first snow I snatched up my coat, pulled on gloves - gloves, off the ski slope! - and ran out into the street, kicking plumes in the air.

They sent me to write snow stories. There were smirks (she'll see what a bother it is). And I did. I got cold, so horribly bone-chilling cold that I wrote letters at night under the blankets and could not remember ever having been warm. I found an old blues, "Cold Wave," and tacked it to my desk.

In April the air went golden all of a sudden and I thought I was going crazy. I was miserable. I called the newspaper and said I could not come to work, because I was crazy. My editor said, it's all right, the rest of us have it too; and that afternoon I learned some about what spring does to certain psyches. I waited, believing by now in the certainty of change, and dug a garden to hurry up summer.

Now this light comes at midafternoon, this port-wine softness that is like nothing I remember on the Pacific coast. I pull single leaves off the elm tree, wondering whether they would survive the airmail trip to my homesick mother in San Francisco.I still have her lumberjack shirt, folded up in the back of my dresser, and I will wear it in October when the first cold comes.