July 1776 has a place in American history books as the month in which the United States declared its Independence. It is now a federal holiday commemorating the adoption of the declaration of independence.
July 1776 also marks another anniversary in history, one involving a founding father and weather. In July of 1776, Thomas Jefferson began a log of weather observations. Stationed in Philadelphia, Jefferson began recording temperatures at various times throughout the day, usually one in the morning, and another in the afternoon or evening. Jefferson also tried to enlist others to do the same and had envisioned a national network of “weather watchers”.
Some of his early observations included not just a thermometer, but also a barometer to measure pressure, and a hygrometer to measure the moisture in the atmosphere. According to his observations, July 4th 1776 saw a temperature of 68 degrees at 6 a.m. and a temperature of 76 degrees at 1 p.m.
