Deities and personifications of seasons

There are a number of deities and personifications associated with seasons in various mythologies, traditions, and fiction.

Winter

Beira, Queen of Winter, also Cailleach Bheur, a personification or deity of winter in Gaelic mythology
Boreas was the Greek god of the cold north wind and the bringer of winter. His name meant "North Wind" or "Devouring One". His name gives rise to the adjective "boreal".
Ded Moroz, a Russian substitute of Santa Claus
Itztlacoliuhqui, deified personification of winter-as-death in Aztecan mythology
Jack Frost
Tengliu, Snow goddess from Chinese mythology.
the Great Winter God, of Ba Jia Jiang, originated from the Chinese folk beliefs and myths
Marzanna, slavic Goddess of Winter, Death, and Rebirth.
Morozko, from a Russian fairy tale, translated as Father Frost
Old Man Winter, personification of winter.
Frau Holle Germanic mother frost.
Skaði is a jötunn and goddess associated with bowhunting, skiing, winter, and mountains in Norse mythology
Three Friends of Winter in Chinese art: the plum, bamboo, and pine.
Nane Sarma, Grandma Frost, Iranian folklore.
General Winter, personification of Winter as a contributing factor to defeat of invading military forces

Ēostre, West Germanic spring goddess; she is the namesake of the festival of Easter in some languages.
Brigid, celtic Goddess of Fire, the Home, poetry and the end of winter. Her festival, Imbolc, is on 1st or 2nd of February which marks "the return of the light".
Persephone, Greek Goddess of Spring. Her festival or the day she returns to her mother Demeter from the Underworld is on 3rd of April.
Many fertility deities are also associated with spring
In Roman mythology, Flora was a Sabine-derived goddess of flowers and of the season of spring
Jarylo, alternatively Yarylo, Iarilo, or Gerovit, is a Slavic god of vegetation, fertility and springtime.
the great Spring God, of Ba Jia Jiang, originated from the Chinese folk beliefs and myths
Zephyrus, the Greek god of the mild west wind, associated with spring

Áine, Irish goddess of love, summer, wealth and sovereignty, associated with the sun and midsummer
the Great Summer God, of Ba Jia Jiang, originated from the Chinese folk beliefs and myths
Freyr, Norse god of summer, sunlight, life and rain

the Great Autumn God, of Ba Jia Jiang, originated from the Chinese folk beliefs and myths

In ancient Greek mythology Anemoi were the gods of wind, some of which were associated with seasons:

Boreas was the north wind and bringer of cold winter air
Zephyrus or Zephyr was the west wind and bringer of light spring and early summer breezes
Notus or Notos was the south wind and bringer of the storms of late summer and autumn. Notos not only brings rain and heavy downpour, but he can also bring extremely hot air especially in the southern parts of Greece.
Eurus was the East Wind & bringer of warmth & rain