León (Spanish pronunciation: [leˈon] ), officially León de Los Aldama, is the most populous city and municipal seat of the municipality of León in the Mexican state of Guanajuato. In the 2020 census, INEGI reported 1,579,803 people living in the city of León and 1,721,215 in the municipality, making it the fourth-most populous city and third-most populous municipality in Mexico. The metropolitan area of León recorded a population of 2,140,094 in the 2020 state census, making it the seventh most populous metropolitan area in Mexico. León is part of the macroregion of the Bajío within the Mexican Plateau, located roughly in the center of the country.
León has a large leather industry, making shoes, boots, belts, jackets, and other leather accessories for national and international markets. The leather industry earned its inhabitants the nickname of "green belly" (panzaverde in Spanish) because of the green tainting in the workers' bodies resulting from treating leather. Its hotel and service industry make it an important commercial center with numerous options for entertainment, gastronomy, leisure activities, arts, and recreation. It is also considered one of the most environmentally friendly cities in Mexico and has a high number of cyclists, in part because of integrating a network of bike lanes into the SIT system. In March 2012, it received an award as "City Water Champion", mainly due to great progress in the areas of sanitation, wastewater reuse, and energy cogeneration from biogas.
In the León area there are ten distinct archeological zones, dating from the pre-classic Mesoamerican period. Most of these are identified with the Chupícuaro culture. By the Classic period, the area was under Teotihuacan and Toltec influence. In the 13th century, the Chichimecas, mostly of the Guamare and Guachichil subgroups, overran the area, migrating from an area of what is now San Luis Potosí. They remained through the Colonial period.
In 1530, Nuño Beltrán de Guzmán arrived with allied Purépecha Indians to the area, naming it Nuestra Señora. Homesteads were granted by the governor of Nueva Galicia Francisco Vásquez de Coronado to Spaniards Rodrigo de Vázquez and Juan de Jasso. Farming and cattle-raising were introduced here around 1546 by the Spaniards, but these settlers were under constant threat by the Chichimecas, who recognized the Spanish as invaders. These settlers requested assistance from the viceregal authorities in Mexico City.
As a response, viceroy Martín Enríquez de Almanza ordered the founding of a city here, with the name of León in 1575. To carry out the order, Juan Bautista de Orozco founded the village of León on 20 January 1576, creating its first town council and laying out its initial streets. In 1580, it attained the rank of "alcadía mayor" meaning it has governing authority of much of the land and smaller towns surrounding it from the Sierra de Comanja to the Lerma River. For example, two other towns founded in the area were San Miguel and Coecillo. In San Miguel, the Spaniards settled the Otomi peoples and in Coecillo were settled the Purépechas, Mexicas and the Chichimecas that did not oppose Spanish rule. As the population of the area grew, a number of municipalities would eventually break off, such as San Francisco del Rincón, Purísima del Rincón (Purísima Concepción), Cd. Manuel Doblado (San Pedro Piedra Gorda), Huanímaro, Abasolo, Cuerámaro and Pénjamo.
In 1582, the first hospital of San Cosme y San Damián was established by Father Espino. The Jesuits arrived to León in 1731, founding the "Compañía Vieja" which is now the site of the Temple of the Immaculate. They also constructed the Temple of the New Company, which would become the cathedral, however they never finished it as they were expelled from Mexico in 1767. On 2 July 1732 arrived an image of Our Most Holy Mother of Light. She would later be declared the patron saint of the city, in 1849.
The population of the area suffered epidemics in 1643, droughts in 1630 and 1712–1714, famines in 1714 and 1786, and flooding in 1637, 1749, 1762, and 1803.
Independence forces under José Rafael de Iriarte arrived to the town on 4 October 1810. However, two months later royalist forces under Felix Calleja retook the locality, with insurrectionist sympathizers facing reprisals. About 2,000 insurgents on horses attacked the town but were repulsed by Count Pérez Gálvez. Royalist forces were attacked here in 1817 by Francisco Javier Mina without success. The town remained in royalist hands until the end of the Mexican War of Independence, when Agustín de Iturbide arrived. The town did not celebrate its first Grito de Dolores to mark independence until 1825. In 1827 it became one of the four "departments" of the newly created state of Guanajuato, and in 1830, it gained city status. In 1840, Father Ignacio Aguado founded the College of San Francisco de Sales and the College of La Madre Santísima was founded in 1844.
During La Reforma war, the city changed hands various times between Liberal and Conservative forces between 1858 and 1860. The most notable battle of that war here was when General José Iniesta attacked the town on 18 February 1859. In that same year, León even separated for a time from the rest of the state of Guanajuato.
In 1862, the bishopric of León was founded, separating the city of León and nine other municipalities such as Irapuato, Guanajuato and Dolores Hidalgo from the bishopric of Michoacán. Bishop Diez de Sollano opened the Conciliar Seminary in 1864. This bishop consecrated the Basilica Cathedral in 1866, even though it was not completed, giving the image of the Virgin of the Light a permanent home.
From 1863 to 1866, the French occupied León during the French Intervention, with Emperor Maximillian visiting the city in 1864. His arrival was much celebrated here, with fireworks and a hot air balloon exhibition put on by the Alemán brothers. However, when Liberal forces finally had permanent control over the town, two incidents occurred. On 30 September 1867, Coronel Cecilio Delgado Estrada ordered his men to shoot over the heads of people who prayed in the streets, causing some to be wounded. Another incident of this type occurred in 1877. The second was more permanent. The Liberals decommissioned the convent and college of Saints Peter and Paul, converting it into offices for city government. It remains such to this day.
On 2 January 1946, a mob gathered in the plaza in front of the municipal palace to protest elections seen as illegitimate. These protesters were fired upon, killing many. This plaza has been named the "Plaza of the Martyrs" in their honor.
Leon generally has a humid subtropical climate (Köppen: Cwa) with summer rainfall (according to Köppen climate classification, Cwa) that closely borders on a semi-arid climate. The average annual temperature is 19.9 °C (67.8 °F), the warmest month is May with a maximum average of 31.7 °C (89.1 °F), and the coolest month is January with a minimum average temperature of 7.7 °C (45.9 °F). Outside the city microclimate island, the ranges tend to be higher, with maximum averages reaching 2 °C higher than in the city, and minimum averages lowered by 3 °C or more. In the villages located in between the northern mountains the climate changes; it is considered subtropical highland climate (Cwb according to Köppen climate classification), the average annual temperature is around 16 °C (61 °F).
Leon averages 681 mm (26.8 in) of precipitation annually, which mainly occurs during the summer and early autumn (from late May through October) generally with thunderstorms in the evening. There is usually a discrepancy about whether Leon's valley is either sub-humid or semi-arid. Depending on the methodology, it can be considered as being either one or the other. With Köppen's methodology, there needs to be more than 678 millimetres (27 in) of annual precipitation for Leon to be considered as humid subtropical; according to several weather stations it may have both (humid subtropical and semiarid) terminologies applied to it. The years considered in the study may also be a determinant factor (more frequently used for international purposes is a 30-year data compilation). Years of average rainfall are rare; the usual pattern is bi-modal, with some large string of dry years usually related to La Niña phenomenon (slightly higher than 300 millimetres (12 in)) followed by other years (around 5) related to El Niño that make up the average (with higher than 39 inches or 990 millimetres). Snowfall is extremely rare. The latest snowfall recorded in Leon was in 1997, although there have been other years of registered slushy snow since 1997.