Map of Paso Robles from PasoWine.com

This past October was a busy month for Paso Robles and the TTB with the announcement of a staggering 11 new American Viticultural Areas (AVAs), all of which are sub-regions of the greater Paso Robles AVA. As of November 10th 2014 these new sub-regional AVAs are official. The road to the establishment of the sub-regional AVA’s has been a long one and started with the filing of the petition in 2007. Filing the petition for one AVA is a complex enough process with many hurdles, now imagine the work that went into filing 11 at the same time!

If you have ever had the occasion to visit Paso Robles you are aware of the diversity of climate and topography this area of California possesses. The aim of these 11 new AVA’s is to highlight these diverse macroclimates.

Here is a closer look at the 11 new AVA’s and what makes them unique

AVA Climate (heat summation scale*) Avg. Annual Precipitation Diurnal Temp change Topography Soil
Paso Robles Maritime climate west side to Continental eastern side 8 to 30 inches 20°F -50°F 600 to 2,400+ feet elevation range Soils both depositional and residual derived from sedimentary rock; moderate depth.
#1 – San Miguel District Region III: 3,000-3,500 degree days 11.4 inches 30°F -35°F 580 to 1,600 feet elevation range Deep, alluvial sandy loams to loams to a few clay loams (some with clay pans) from the river bottoms up onto the higher terraces.
#2 – Adelaida District Region II: 2,500-3,000 degree days TO Region III: 3,000-3,500 degree days 25 inches 30°F 900 – 2200 feet elevation range Shallow, bedrock residual soils and patchy colluvial hillside soils from middle member of Monterey For-mation and older rocks; largely calcareo
#3 – Paso Robles
Estrella District
Region III: 3,000-3,500 degree days 12.5 to 15.5 inches 30°F -40°F 745 – 1819 feet elevation range Quaternary alluvial soils of diverse ages across young-er to older terraces, deep to moderate depth, with rem-nant patches of older valley fill at highest e
#4 – Paso Robles
Willow Creek District
Region II: 2,500-3,000 degree days 24 to 30 inches 20°F 960 – 1,900 feet elevation range Mostly bedrock (residual) soils from the middle and lower members of the Mon-terey Formation, patches of alluvial soil along streams, largely calcareous, loams to clay loams.
#5 – Paso Robles Geneseo District Region III: 3,000-3,500 degree days TO Region IV: 3,500-4,000 degree days 13 to 14 inches 20°F -25°F 740 – 1,300 feet elevation range Old alluvial terrace and re-sidual hillside soils of mod-erate depth with cementa-tion of the gravelly Paso Robles Formation and older granites.
#6 – San Juan Creek Region III: 3,000-3,500 degree days TO Region IV: 3,500-4,000 degree days 10.4 inches 35°F -40°F 980 – 1,600 feet elevation range Well to moderately drained, deep alluvial soils, sandy loams to loams to clay loams on the highest, oldest terraces.
#7 – Templeton Gap District Region II: 2,500-3,000 degree days 20 inches 20°F 700 – 1,800 feet elevation range Broad alluvial terraces and fans of Paso Robles Creek and the Salinas River over bed- rock; alluvial soils of shallow to moderate depth and sandy to silty to clay loams; calcareous in places.
#8 – El Pomar District Region II: 2,500-3,000 degree days 15 inches 20°F -25°F 740 – 1,600 feet elevation range Quaternary alluvial soils, well developed loams to clay loams, some calcare-ous, with Monterey For-mation sand- stone and silt-stone at depth in some are-as
#9 – Creston District Region III: 3,000-3,500 degree days 11.5 inches 25°F 1,000 – 2,000 feet elevation range Old, well developed terrace and hillside soils; mix of granitic and sedimentary rocks
#10 – Paso Robles Highlands
District
Region IV: 3,500-4,000 degree days 12 inches 50+°F 1,160 – 2,086 feet elevation range Deep, sometimes cemented alluvial soils; old leached alkaline soils common, with younger sandy soils along active steams.
#11 – Santa Margarita Ranch Region II: 2,500-3,000 degree days 29 inches 25°F 900 – 1,400 feet elevation range Deep alluvial soils derived from many lithologies and varying in texture, with patchy residual soils on mountain slopes.

*The UC Davis heat summation scale is organized into five tiers. Region I is the coolest and Region V is the warmest.

climate data from PasoWine.com