Hadley was born in London, England in February of 1685 to Katherine FitzJames and George Hadley. He had an unremarkable childhood, and was eclipsed in his early years by his older brother John, the inventor of the reflecting telescope and the octant (a precursor to the sextant).
In 1686, Edmond Halley proposed his theory attempting to explain the Trade Winds. While Halley's theory was successful in describing the overall circulation at the equator, it failed completely to explain the westward component of the Trades. Had it been successful in doing so, Hadley's historical presence would have been greatly diminished. However, in realizing that the Earth's rotation played a crucial role in the direction taken by a moving airmass, Hadley earned fame.
Hadley was elected a Royal Fellow in 1745 and died in 1768.