San Antonio Oeste is a port city in the Argentine province of Río Negro, and head of the department of San Antonio. The town is bordered by its sister communities of San Antonio Este, to the east, and Las Grutas, to the southwest. Discovered by an expedition of the Spanish Empire in 1779, San Matías Gulf became the site of an outpost, San Antonio (so named in honor of St. Anthony of Padua). Water scarcity led the original settlement to fail in 1905, leading the community to settle west of the gulf, in what today is San Antonio Oeste. The arrival of the Buenos Aires Great Southern Railway in its expansion towards Bariloche in 1910 led to the hamlet's growth. It later became the site of Punta Verde, the leading port for the large wool export industry of Patagonia, though the collapse in the wool market during the 1930s and 1940s led to the port's closure in 1944. San Antonio Oeste benefited afterwards from a growth in tourism in nearby Las Grutas, a scenic cove known for its grottoes. Since 2000, it has also been home to a growing fishing industry, resulting from the opening of a deep-water port in San Antonio Este. Climate San Antonio Oeste has a semi-arid climate (Köppen climate classification BSk) with cool winters and hot summers. Winters are characterized with cool temperatures during the day and very cold nights. In the coldest month, June and July, the mean temperature is . Temperatures can regularly fall below freezing during the winter months although snowfalls rarely occur, averaging 0.2 days with snow per year. During this time of the year, the weather is characterized by cloudy weather in which an average of 9–11 overcast days are recorded per month. Spring and fall are transition seasons featuring mild daytime temperatures and cool nighttime temperatures. Spring starts out cool, with frosts that occur regularly in September with the last date of frost occurring on October 2. However, frosts can occur as late as November 4 It is also a windy season, which can make the temperature feel cooler than it should be. Autumn starts out warm but increasingly becomes cooler in April and May with the frosts that can occur as early as March 26. Normally, the first date of frost occurs on April 28. Summers are hot during the day while nighttime temperatures are mild. It tends to