Next to only its natural beauty, Lupin’s most appealing feature may be its superb micro-climate, perhaps the sunniest in the Bay Area, especially during the sometimes fog-shrouded summers, as our San Francisco members will attest. Lupin’s warm, sunny slopes, located just beyond the moderating coastal mist, provided the fruitful site of a pre-prohibition California vineyard.
The prime sunning season at Lupin tends to run from April, when wildflowers are in fullest bloom, through October. By June the mostly cloudless days have normally turned the winter grasses from green to gold, and rainfall becomes truly rare until mid-autumn. Daytime high temperatures typically range from 70-90°F while nighttime lows are usually in the 50-60°F range.
Even the cooler, less-popular period from November through March remains comfortable compared to most locales. Though rain on any given day is more probable, it is not unusual to find sunbathers around the heated pools at Lupin while most of the country shivers. Off-season highs normally run from 55-75° F with lows most often falling to 30-40° F levels.