There are an average of 16.4 days with highs of 90 °F (32 °C) or higher and an average of 138.8 days with lows of 32 °F (0 °C) or lower.The record high temperature was 107 °F (42 °C) on June 28, 2012.
Normally, July is the wettest month with an average of 3.89 inches (9.9 cm) and February is the driest month with an average of 1.84 inches (4.7 cm).
The most precipitation in one month was 12.00 inches (30.5 cm) in June 1981.
The most precipitation in 24 hours was 4.63 inches (11.8 cm) on September 18, 1907.
The city contains the site of Fort Defiance, built by General "Mad" Anthony Wayne in August 1794, during the Northwest Indian War, at the confluence of the Auglaize and Maumee rivers.
General Wayne surveyed the land and declared to General Scott, "I defy the English, Indians, and all the devils of hell to take it." This area became Fort Defiance.
Today a pair of cannons outside the city library on the Maumee River overlook the confluence and mark the location of Fort Defiance, along with a mounded outline of the fort walls. From Fort Defiance, the American forces moved northeast along the Maumee River to fight the decisive Battle of Fallen Timbers near the current town of Maumee, Ohio.
This victory secured for the United States the Northwest Territory, now the states of Ohio, Michigan, Indiana, Illinois, and Wisconsin.
Fort Winchester was built on the same spot during the War of 1812, but it was a larger fort that extended southward somewhat along the Auglaize River.
Historical plaques in the sidewalks mark the full extent of Fort Winchester. In 1845 it was made the county seat of the newly created county, and in 1881 it became a city.