Chilli pepper seeds are usually sown from February to the end of April.  However, these vegetables command a long growing season, requiring sufficient time for the plants to mature and their fruit to develop and ripen.  Accordingly, I find that chilli peppers are best started from seed sown in January.

Nurseries stock a limited range of chilli pepper plants in springtime, but gardeners who grow chillies from seed are blessed with the choice of a vast range of varieties.