Then Nyx, somehow all by herself, had a daughter named Hemera, who was Day. Those two never got along because they were as different as . . . well, you know.

Percy Jackson, in Percy Jackson's Greek Gods

Hemera is the Greek Primordial Goddess of the day. She is the female counterpart of her brother and consort Aither, with whom she had one child: Thalassa, a Protogenos of the Sea. Hemera is a daughter of Nyx. Her Roman aspect is Dies.

Percy Jackson's Greek Gods

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Nyx, her mother.

Hemera (Day) was born from Nyx (Night), through parthenogenesis (by herself). In the evening, her mother Nyx drew a veil of darkness between the shining atmosphere of her brother Aither and the lower air of earth (Chaos) bringing night to man. With each morning Hemera dispersed night's mists, bathing the earth again in the shining light of heaven (Aither).

Hemera eventually marries Aither, whom she has a daughter, Thalassa. In ancient times, she, her mother Nyx (whom she usually fights with), her husband Aither, and the stars were the constant company of her uncle Ouranos in the sky.

Percy Jackson's Greek Heroes

Hemera is briefly seen by Phaethon, when the latter visits the palace of his father Helios, the Titan of the Sun.

The Heroes of Olympus

The House of Hades

When confronting Nyx, Percy Jackson and Annabeth Chase pretended to be tourists, unimpressed by the Primordial of Night. But they added that Hemera might be more interesting. Offended, Nyx snapped that Hemera (Day) was her daughter, so Night was much more impressive than Day.


In Percy Jackson's Greek Heroes, Hemera is described as a beautiful woman in shimmering blue-and-gold robes.


Hemera presumably has a goddess' powers, but is extremely powerful, as she is one of the Protogenoi.

  • Pyrokinesis: As the Primordial Goddess of Day, Hemera has divine authority and control over fire.
    • Heated Fire: She can control the heat of her fire.
    • Fire Extinguishing: She can put out any amount of fire without losing energy.
    • Fire Blasts: It is assumed that she can launch projectile blasts of flame at opponents.
    • Fire Teleportation: It is possible that she can teleport in columns of flames.
  • Photokinesis: As the Primordial Goddess of Day, Hemera has absolute control over light, similar to her husband.
    • Create a ball or shape of light to blast.
    • Create light shields/force fields.
    • Create illusions/hallucinations.
    • Blast of light to impale or blind enemies for some time or maybe forever.
    • Project healing energies. This ability is different from Vitakinesis.



  • Curiously, Hemera and her brother Aither are the only children of Nyx and Erebos who are Protogenoi even with the others being feelings or things, like Thanatos are the Death, Hypnos is the Sleep, etc.
    • With her mother and step-father, his uncle Ouranus and his aunt Gaea, the latter and his uncle Tartarus,  and she and her brother-husband Aither, they are the only known Protogenoi who "generate" another Protogenoi through sex.
  • In the ancient cosmogonies night and day were substances distinct and quite independent from the sun.
  • Her Norse equivalent is Dagr.
  • Hesiod appears to regard Hemera as more of a divine substance rather than anthropomorphic goddess.
  • Some myths say that he and Hemera are the parents of the Nephelae and of the others sky or wind nymphs and creatures, like birds and aurae.
  • In different myths, Hemera is a daughter of Nyx and Chronos (Time). She is also the mother of Ouranos and Gaea.
  • Hemera was closely identified with Hera, the Queen of Olympus, and Eos, goddess of the dawn.
    • Hemera was largely irrelevant in mythology, with her role being wholly subsumed by the goddess Eos.
      • Pausanias seems to confuse her with Eos when saying that she carried Cephalus away. He makes this identification with Eos upon looking at the tiling of the royal portico in Athens, where the myth of Eos and Kephalos is illustrated.
      • Pausanias makes this identification again at Amyklai and at Olympia, upon looking at statues and illustrations where Eos (Hemera) is present.
The Heroes of Olympus
Core Series: The Lost Hero | The Son of Neptune | The Mark of Athena | The House of Hades | The Blood of Olympus
Main Characters: Jason Grace | Piper McLean | Leo Valdez | Percy Jackson | Frank Zhang | Hazel Levesque | Annabeth Chase | Reyna Ramírez-Arellano | Nico di Angelo | Gleeson Hedge
Secondary Characters: Hylla Ramírez-Arellano | Dakota | Tyson | Ella | Octavian | Halcyon Green | Dr. Howard Claymore | Alabaster C. Torrington | Iapetus/Bob
Minor Characters: Rachel Elizabeth Dare | Grover Underwood | Thalia Grace | Fleecy | Mrs. O'Leary | Arion | Calypso | Lou Ellen Blackstone | Chiron | Will Solace | Tristan McLean | Don | Julia
Olympian Gods: Zeus | Hera | Poseidon | Hades | Ares | Demeter | Athena | Apollo | Artemis | Hephaestus | Aphrodite | Hermes | Dionysus
Minor Gods: Achelous | Aeolus | Asclepius | Boreas | Eurus | Hecate | Iris | Hypnos | Keto | Khione | Kymopoleia | Mithras | Nemesis | Nike | Notus | Phorcys | Serapis | Thanatos | Triptolemus | Zephyros
Roman Gods: Jupiter | Juno | Neptune | Pluto | Mars | Minerva | Ceres | Lupa | Bellona | Fortuna | Janus | Terminus | Vulcan | Mercury | Apollo (Roman) | Diana | Venus | Bacchus | Pomona | Aquilon | Hercules | Cupid | Auster | Favonius | Letus | Victoria | Orcus
Giants: Enceladus | Porphyrion | Alcyoneus | Polybotes | Ephialtes | Otis | Damasen | Clytius | Mimas | Orion | Hippolytus | Thoon | Periboia
Undead: Medea | Midas | Lityerses | Gray | Phineas | Otrera | Echo | Narcissus | Sciron | Pasiphaë
Primordial Gods: Gaea | Tartarus | Ourae | Nyx | Chaos | Ouranos | Akhlys | Erebos | Hemera | Elpis | Spes
Related Content: Rick Riordan | Percy Jackson and the Olympians | Demigods and Monsters | The Ultimate Guide | The Demigod Files | The Demigod Diaries | The Son of Sobek | The Singer of Apollo | The Staff of Serapis | Percy Jackson's Greek Gods | Percy Jackson's Greek Heroes | The Crown of Ptolemy | Demigods & Magicians | Demigods of Olympus | Percy Jackson Demigod Collection
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