It is technically part of the continental U.S., but is not usually included in the colloquial use of the term; Alaska is not part of the contiguous U.S., often called "the Lower 48".
ɪɾ ɪz tˈɛknɪkli pˈɑːɹt ʌvðə kˌɑːntɪnˈɛntəl jˈuː.ˈɛs., bˌʌt ɪz nˌɑːt jˈuːʒuːəli ɪŋklˈuːdᵻd ɪnðə kəlˈoʊkwɪəl jˈuːs ʌvðə tˈɜːm; ɐlˈæskə ɪz nˌɑːt pˈɑːɹt ʌvðə kəntˈɪɡjuːəs jˈuː.ˈɛs., ˈɔfən kˈɔːld "ðə lˈoʊɚ fˈoːɹɾi ˈeɪt".