Summer sits next to 3 phonetic neighbors — Somer, Simmer, and Amber are the closest matches by sound. Most share Summer's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"born in summer"
"dark-haired, dark"
"king's meadow"
"beloved, much loved"
"jade stone, precious green gemstone"
"noble natured"
"God will add, God shall increase"
"famous, illustrious"
"precious gem, pearl of great price"
"fleet of ships"
"flower named for botanist Pierre Magnol"
"young ceremonial attendant"
"heavenly, of the sky"
"born at dawn"
"exalted, sublime"
"beautiful, graceful"
"ardor, enthusiasm, fire"
"sorrows"
"woman from Magdala (tower)"
Similar sound: These names share phonetic patterns with Summer — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have English origins, giving them the same cultural heritage as Summer.
Rhythm: Summer is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.