← Data

Mr. Jefferson’s Weather

21,823 observations, 1776–1826 · begun in Philadelphia, July 1, 1776

Historic Layers: Virginia 1755 — the Fry–Jefferson Map of the Most Inhabited Part of Virginia, surveyed by Joshua Fry and Peter Jefferson, Thomas’s father. Library of Congress scan, warped onto the modern map.

France 1750s — the Carte de Cassini, the first survey of an entire nation by triangulation, drawn while Jefferson lived in Paris. BnF scan via IGN.
Data: The Jefferson Weather & Climate Records, © The Trustees of Princeton University (CC BY-NC-SA 4.0). Coordinates added; some locations approximate. Historic maps: Fry & Jefferson 1755 (Library of Congress); Carte de Cassini (BnF / IGN).