Dublin is city in the "tri-valley area" of Northern California (Dublin, Pleasanton, Livermore) across the bay from San Francisco. It's a developing city, with a lot construction, residential and commercial, taking place on the eastern periphery, where there is an abundance of flat, rolling countryside that is home to deer, coyote and jack rabbit.
The winter weather is typical of Northern California, with the temperature rarely dropping below freezing. However, it is quite warm here in the summer with the mean temperature in July around 90, often getting into the high 90's. Two years ago, the temperature rose to 114, probably a record, but the heat is offset by a strong westerly wind, which makes it very pleasant when the temperature is around 80, which it often is. The cost of living is quite high, however, as it is in most parts of the San Francisco Bay Area. We get virtually no rain during the summer and fall, but it does rain a fair amount in the winter and spring.
The Bay Area Rapid Transit (BART) train runs from San Francisco to Dublin (about a 45-minute trip) and to other parts of the Bay Area, which is convenient for commuting, especially if you live in Dublin and work in San Francisco. I should mention that the Santa Rita Jail (for Alameda County) is located here, but that does not seem to have affected the security of the community, as there are virtually no homeless in Dublin and the crime rate is quite low by national standards.
If you've got the money, this is an attractive place to live.