History of San Luis Obispo, California in Timeline

By Popular Timelines Editorial Team · Updated: October 14, 2025

San Luis Obispo is a city located on the Central Coast of California, serving as the county seat of San Luis Obispo County. Situated approximately midway between the San Francisco Bay Area and Los Angeles, it had a population of 47,063 as of the 2020 census. It is a notable city within the state.

1904: Origins of Poly Royal

The origins of Poly Royal trace back to the 1904 Farmer's Institute and Picnic Basket.

1922: Snowfall in San Luis Obispo

In 1922, about 0.3 inches (0.76 cm) of snowfall was recorded in San Luis Obispo, although it was not officially recorded.

December 11, 1932: Coldest day recorded

On December 11, 1932, San Luis Obispo experienced its coldest day on record, with a temperature of 40 °F (4 °C).

1933: Beginning of Poly Royal

Poly Royal, Cal Poly's open house, was held annually beginning in 1933.

September 22, 1939: Warmest night recorded

On September 22, 1939, San Luis Obispo experienced its warmest night on record, with a temperature of 75 °F (24 °C).

1940: FlixBus location

FlixBus boards from the San Luis Obispo Railroad Museum at 1940 Santa Barbara Avenue.

1945: Cancellation of Poly Royal due to war rationing

In 1945, Poly Royal was cancelled due to war rationing.

1958: Establishment of the Madonna Inn

In 1958, the Madonna Inn, an eccentric landmark, was established by Alex Madonna in San Luis Obispo.

1960: Gum sticking on the walls of Bubblegum Alley

Since about 1960, people have been sticking chewed gum on the walls of Bubblegum Alley in San Luis Obispo.

1982: Ordinance forbidding drive-through businesses approved

In 1982, the city council approved an ordinance forbidding the construction of "drive-through" businesses.

1985: High attendance at Poly Royal

In 1985, Poly Royal drew 126,000 people to San Luis Obispo.

1988: Snow flurries reported

In 1988, snow flurries were reported in San Luis Obispo.

June 1990: Proposal of city ordinance to ban smoking

In June 1990, City Councilman Jerry Reiss proposed a city ordinance to ban smoking in all indoor public areas.

June 19, 1990: City Council votes in favor of ordinance to ban smoking

On June 19, 1990, the San Luis Obispo City Council voted 4–1 in favor of an ordinance to ban smoking in all indoor public areas.

August 2, 1990: San Luis Obispo bans smoking in all public buildings

On August 2, 1990, San Luis Obispo became the first municipality in the world to ban smoking in all public buildings, including bars and restaurants.

1990: Last Poly Royal held

Cal Poly held its last Poly Royal in 1990.

June 2000: Beginning of The Bike Happening

Since June 2000, the first Thursday of every month has been The Bike Happening (also known as Bike Nite) in San Luis Obispo, with bikers gathering at the Mission Plaza.

2005: Cancellation of Mardi Gras parade

In 2005, the Mardi Gras parade in San Luis Obispo, one of the largest west of the Mississippi, was canceled.

2006: Snow flurries reported

In 2006, snow flurries were reported in San Luis Obispo.

2007: Fire Department information

As of 2007, the San Luis Obispo fire department had 45 full-time firefighters and four fire stations.

2007: Designation as Bicycle Friendly Community

In 2007, San Luis Obispo was designated as a Bicycle Friendly Community at the Gold level by the League of American Bicyclists.

2007: Opening concert of the Forbes Pipe Organ

In the summer of 2007, the Forbes Pipe Organ had its opening concert. The organ was built elevated into a side wall of Harmon Hall in the Christopher Cohan Performing Arts Center on the Cal Poly campus and required the donation of a further $3 million for purchase and installation.

2008: City Council votes to keep ban on drive-through businesses

In 2008, the San Luis Obispo City Council voted 3–2 to keep the ban on the construction of "drive-through" businesses.

March 12, 2009: Greyhound closes station building

On March 12, 2009, Greyhound closed its station building in San Luis Obispo, but still serves the city via a bus stop on Railroad Avenue.

April 2010: San Luis Obispo strengthens its anti-smoking legislation

In April 2010, San Luis Obispo strengthened its anti-smoking legislation, making smoking in public a citable offense beginning on June 20, 2010.

April 2010: "Unruly gathering" ordinance passed

In April 2010, an "unruly gathering" ordinance passed with a vote of 4–1 in San Luis Obispo.

June 20, 2010: Strengthened anti-smoking legislation goes into effect

On June 20, 2010, San Luis Obispo strengthened its anti-smoking legislation, making smoking in public a citable offense.

2010: San Luis Obispo population reported by US Census

In 2010, the United States Census reported that San Luis Obispo had a population of 45,119. The racial makeup of San Luis Obispo was 38,117 (84.5%) White, 523 (1.2%) African American, 275 (0.6%) Native American, 2,350 (5.2%) Asian, 65 (0.1%) Pacific Islander, 1,973 (4.4%) from other races, and 1,816 (4.0%) from two or more races.

2016: PG&E announces closure of Diablo Canyon Nuclear Power Plant

In 2016, Pacific Gas and Electric (PG&E) announced the closure of the Diablo Canyon Nuclear Power Plant in 2025.

2017: Museum launches a Capital Campaign for a new building

The San Luis Obispo Museum of Art launched a $15 million Capital Campaign for a new building in 2017.

2019: SLO experiences boom in home construction

In 2019, San Luis Obispo experienced a boom in home construction, accompanied by continued building of commercial structures. Due to housing not keeping up with job growth, many people commute to their jobs in San Luis Obispo.

September 6, 2020: Hottest temperature on record

On September 6, 2020, the hottest temperature on record was officially recorded at 113 °F (45 °C) in San Luis Obispo, although a 120 reading was reported in the local news.

2020: Air service to Portland and San Diego begins

Beginning in 2020, San Luis Obispo County Regional Airport began service to Portland and San Diego.

2020: San Luis Obispo population reported by US Census

In 2020, the United States census reported that San Luis Obispo had a population of 47,063. The racial makeup was predominantly White (72.6%), with smaller percentages of African American (1.1%), Native American (0.7%), Asian (6.2%), Pacific Islander (0.1%), and other races.

2020: Population at the 2020 census

In 2020, the population of San Luis Obispo was recorded at 47,063 during the United States census.

2021: Top employers listed in city's Comprehensive Annual Financial Report

According to the city's 2021 Comprehensive Annual Financial Report, the top employers in the city were listed.

2021: Water Resource Recovery Facility Upgrade

In 2021, the Water Resource Recovery Facility was undergoing a plant upgrade expected to be completed.

2023: Cal Poly Enrollment

As of fall 2023, California Polytechnic State University (Cal Poly) enrolled 21,497 students.

2023: Median household income reported by US Census Bureau

In 2023, the US Census Bureau estimated that the median household income was $66,711, and the per capita income was $45,462 in San Luis Obispo. Approximately 6.5% of families and 30.0% of the population were below the poverty line.

2025: Expected closure of Diablo Canyon Nuclear Power Plant

In 2016, Pacific Gas and Electric (PG&E) announced the closure of the Diablo Canyon Nuclear Power Plant in 2025, but it was later granted an extension.