The street with gentle rain as soft as butter is located in San Francisco, California. San Francisco is renowned for its unique microclimate, which often results in a mild and gentle rainfall. The city's geography, with its hills and proximity to the Pacific Ocean, contributes to the soft and buttery quality of the rain. The famous "microclimates" of San Francisco, where different neighborhoods can experience varying weather conditions, further enhance the city's reputation for gentle rain.

San Francisco's climate is characterized by a Mediterranean-type climate, with cool, moist summers and mild, wet winters. The city receives an average of 21.2 inches (540 mm) of precipitation annually, with the majority falling between October and April. The gentle rain is often accompanied by fog, which is another characteristic of San Francisco's weather. The combination of fog and rain creates a serene and tranquil atmosphere that is often described as "soft" or "gentle.

Data from the National Weather Service (NWS) supports the notion that San Francisco has a reputation for gentle rain. According to the NWS, San Francisco has an average of 49.4 days with measurable precipitation per year. This is significantly lower than other cities in the United States, such as Seattle, which has an average of 152.6 days with measurable precipitation per year. The lower number of precipitation days in San Francisco contributes to the perception of gentle rain.

Additionally, the city's elevation plays a role in the gentle nature of the rain. San Francisco is situated at an elevation of approximately 52 feet (16 meters) above sea level. This elevation, combined with the city's coastal location, results in a relatively mild and gentle rainfall. The rain that does fall is often light and steady, rather than heavy and intense.

In conclusion, the street with gentle rain as soft as butter is found in San Francisco, California. The city's unique microclimate, Mediterranean-type climate, and coastal location contribute to the gentle and soft nature of the rain. Data from the National Weather Service further supports the perception of San Francisco as a city with gentle rain.