Do summer and somewhere have the same vowel sound?

No, "summer" and "somewhere" do not have the same vowel sound.

* Summer: The vowel sound in "summer" is a short "u" sound, similar to the vowel sound in "cup" or "sun".

* Somewhere: The vowel sound in "somewhere" is a long "e" sound, similar to the vowel sound in "see" or "tree".