Begin every month with a capital
January through December are names, so each begins with a capital letter. When checking a spelling, inspect the first letter as well as the letters inside the word.
Use two shared endings
January and February both end in the written chunk uary. September, October, November, and December all end in ber. Spell the beginning of each word, then attach the shared ending without changing it.
Group the shorter month names
March ends with the consonant team ch. April and August each have two syllables; August begins with the vowel team Au. May, June, and July use three different ways to spell their main vowel sounds: ay in May, final e helping u in June, and final y in July.