I no longer due themes ~ I follow a more emergent child led curriculum of 'back to basics' .... within that I also do a very laid back version of the Jolly Phonics program within that emergent curriculum scope so each month we cover 2 letter sounds ... so this month we are on sounds H and R and I will add things to the program in way of props in playroom, in sensory bins, during circle time, meals or snacks planning etc to help reinforce those letter sounds with the children and than if the children show interest in learning more about something I have added to spark their interest than we will explore that more ... so over the years we have done little projects on Apple seeds, Bats, Snakes, Rainbows, Trains, Horses, work with Flashlights and exploring light and dark concepts and so forth ... so every year is 'different' depending on the crew and sometimes we spend a long time on one 'topic' cause that is where their interest lies but all their areas of developmental domains are covered within that ... so they are still learning letters, numbers, social skills, physical development mastery and so forth.

I worked with themes for eons at the start of my career though if that is what you feel most comfortable with I can share what were common monthly themes back in the day ...

September ~ All about Me and my Family (family, body parts, health and nutrition concepts)
October ~ Thankful for Halloween (Thanksgiving / Fall / Halloween)
November ~ Crazy Concepts (shapes / letters / numbers / opposites)
December ~ Holidays around the World (baking and learning about different holiday traditions)
January ~ Winter & its Animals (exploring snow / hibernation concepts)
February ~ Emotions / Valentines
March ~ Down on the Farm for Easter (flipped with April theme depending on when Easter falls)
April ~ Circus / Zoo Fun or Dinosaurs / Volcanoes
May ~ Creeping into Spring (bugs, insects, planting and spring concepts)
June ~ Nursery Rhymes and Fairy Tales
July ~ Summer Sports Fun / Camping / Olympics
August ~ Community Helpers / Safety / Nutrition