Climate Livermore, California

wind turbines, part of altamont pass wind farm near livermore

livermore has mediterranean climate, although close semi-arid climate because of relatively low annual precipitation. features warm hot, dry summers , mild cool, wet winters (köppen climate classification csa). summer (june–october) daytime temperatures average in 75 85 °f (24 29 °c) range, reach 100 °f (38 °c) , can approach 110 °f (43 °c). summer nights, however, cooler, lows in 50 60 °f (10 16 °c) range. valley s passes direct normal west east flow of air through valley. there strong evening wind in summer brings cool air off pacific ocean livermore valley heads towards hotter central valley. wind strong enough average summer wind speed of 9 miles per hour (14 km/h) , predictable enough make livermore hills covered wind turbines mounted in altamont pass. period june september extremely dry , characterized clear skies, in late summer, subtropical moisture surges livermore valley, bringing high humidity, monsoon clouds, and, less commonly, thunderstorms.

nearly of 14.6 inches (370 mm) of annual livermore rainfall comes in september may time period, 50% of days sunny during period no appreciable cloud cover. peak rainy months december march. rainstorms classified 50% light rain, 32% moderate rain, 11% heavy rain , less 6% thunder showers. coldest months december , january, mean high of 56 °f (13 °c) , low of 38 °f (3 °c) occasional frost possible on clear mornings. temperature can drop low 20 25 °f (−7 −4 °c) range on exceptionally cold night. snow rare, light dustings occur on surrounding hills , in valley.

the record high temperature 115 °f (46 °c), recorded on september 3, 1950, , record low temperature 18 °f (−8 °c), recorded on january 5, 1961, , december 9, 1972.