Yes, according to the Hokku calendar and the old European agricultural calendar, now that we have passed Halloween, winter has begun. It certainly seems like it where I am, because the skies are dim and grey, clouds are low, and now and then a cold rain falls.
Winter, in the Hokku Year, is the time when one turns inward, a time for introspection. That is so because in Nature, winter is the time when people were (and still are, to some extent) often secluded because of bad weather, cold and snow.
It is a time when contrasts become very obvious — the warmth of an indoor fire when frost laces the windowpanes with icy ferns, a warm cup of something on a cold morning, stars shining in the long, dark nights.
Winter becomes the bleakest time in the year, spare and austere, and so it is the time when small comforts are most highly appreciated — good food and helpful friends and warm blankets.
In the daily cycle, winter corresponds to the middle of the night;
In human life, winter corresponds to very old age and death, because it is the time when we see the plants advanced in withering or standing dead and dry in the frosty fields. It is the time when the sap of life has fallen in the trees, when life and energy have left leaves and branches and return to the root.
So that is winter, a time of turning inward, of returning to the root. In writing hokku, it is a good time to notice opposites, warmth versus cold, light versus darkness, sounds versus silence, motion versus stillness, because such things are very much in keeping with the nature of the season. It is also a good time to write about solitude.
Winter brings the further lowering of the arc of the sun across the sky, a continued weakening of the Yang energies in Nature until they reach their lowest point. And then in midwinter a spark of Yang appears, the Wheel of the Year continues to turn, the arc of the sun slowly ascends again, and the cycle begins anew.