It is about 32 miles (51 km) due east from the Pacific Ocean and within a rain shadow of the Santa Lucia Coast Range, so it has a warmer and more continental climate than some of the other Paso Robles sub-appellations to the west.

The San Juan Creek area has long been a ranching, vineyard, and field and row crop farming community.

At one point attracting a fledgling farmer, Walter Knott, into growing produce for the ranch hands in the area and selling what was not consumed.

[2][5] Broad alluvial plains, constructed by the Estrella River and its tributary streams, dominate the topography of the San Juan Creek viticultural area.

The lowland alluvial plains of the San Juan Creek viticultural area are surrounded by the steep Cholame Hills of the Temblor Range slopes to the north and east.

Although some vineyards are planted on steep slopes with southerly and northerly aspects, the viticultural area's vineyards are generally located on flat land and gentle slopes with less than eight degrees incline, which exposes them to day-long direct sunlight, cooling breezes from mountain-valley winds, and occasional sea breezes.

With the abundance of sunshine in the San Juan Creek AVA, moderate yields are common with earlier harvest dates than in the cooler regions to the west.

The Salinas River runs northward through the region, eventually emptying into Monterey Bay, outside the Paso Robles viticultural area.

During summer and fall afternoons, sea breezes from Monterey Bay occasionally travel up the Salinas River valley into the Paso Robles region.

The southwestern portion of the Paso Robles viticultural area lies along the crest and eastern slope of the Santa Lucia Range and marine air off the cool Pacific Ocean will spill west-to-east through a series of gaps in the crest of the Santa Lucia Range, creating sea breezes in the Paso Robles area.

The frequency and duration of the sea breezes incrementally diminish inland, and the lessening of these marine influences affects the native vegetation and agricultural potential of the various areas of the Paso Robles region.

In addition to the cooling influence of the marine breezes, cold air drains off the mountain slopes of the Santa Lucia Range at night and into the Paso Robles viticultural area.

Alluvial plains and terraces; elevations between 980 and 1,600 feet (300–490 m); strong continental influence; average annual rainfall of 10.4 inches (260 mm); transitional Winkler Region III to IV climate.

The best developed soils in the San Juan Creek viticultural area are on the oldest alluvial fans, especially along the north side of the Estrella River, close to the northern portion of the proposed boundary.

[2] San Juan Creek can get exceptionally warm during the summer as it is a Region III–IV, although the nights still get quite cool with an average diurnal temperature swing of 35 to 40 °F (2–4 °C).