Dissimilation may occur when a word contains two identical or closely related sounds, resulting in the change or loss of one of them. This happens regularly in February, which is more often pronounced \ˈfe-b(y)ə-ˌwer-ē\ than \ˈfe-brə-ˌwer-ē\, though all of these variants are in frequent use and widely accepted. The \y\ heard from many speakers is not an intrusion but rather a common pronunciation of the vowel u after a consonant, as in January and annual.
Word History
Etymology
Middle English Februarie, from Old English Februarius, from Latin, from Februa, plural, feast of purification
First Known Use
before the 12th century, in the meaning defined above
Time Traveler
The first known use of February was before the 12th century