Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 92091 — Rancho Santa Fe, CA

ZIP code 92091 (Rancho Santa Fe, San Diego County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 92091 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone10a30 to 35 °F
Coldest night−1.1 to 1.7 °C
Last frostrare
First frostrare
2012 zone10a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 10a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Rancho Santa Fe, CA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates

A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Rancho Bernardo, CA — 6 miles away, elevation 689 ft) the median growing season is 365 days. When frost does come, it is a midwinter night or two; cover tender plants when a freeze is forecast.

Frost data: NOAA NCEI U.S. Climate Normals 1991–2020.

When spring arrived in 2026

In 2026, spring leaf-out near 92091 came on Jan 18 — 4 days earlier than the 1991–2020 average (Jan 22).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in Rancho Santa Fe, CA

The soil mapped at the center of ZIP 92091 is Huerhuero — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Huerhuero loam, 2 to 9 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 92091; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Rancho Santa Fe, CA

Summer high83 °Faverage high, August
Winter low44 °Faverage low, December
Hot days21days a year at 90 °F or more
Freezing nights1nights a year at 32 °F or less
Growing degree days4,953base 50 °F — the season’s usable heat
Longest day14 h 20 mindaylight on June 21
Shortest day9 h 58 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation12.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 67 °F, low 46 °F 67°46° JanFebruary: average high 67 °F, low 46 °F 67°46° FebMarch: average high 68 °F, low 49 °F 68°49° MarApril: average high 70 °F, low 51 °F 70°51° AprMay: average high 72 °F, low 55 °F 72°55° MayJune: average high 76 °F, low 58 °F 76°58° JunJuly: average high 82 °F, low 63 °F 82°63° JulAugust: average high 83 °F, low 64 °F 83°64° AugSeptember: average high 81 °F, low 60 °F 81°60° SepOctober: average high 78 °F, low 57 °F 78°57° OctNovember: average high 71 °F, low 50 °F 71°50° NovDecember: average high 66 °F, low 44 °F 66°44° Dec

Precipitation by month inches

0″1″2″3″January: 2.44 in precipitation 2.4 JanFebruary: 2.99 in precipitation 3.0 FebMarch: 1.83 in precipitation 1.8 MarApril: 1.15 in precipitation 1.1 AprMay: 0.36 in precipitation 0.4 MayJune: 0.09 in precipitation 0.1 JunJuly: 0.09 in precipitation 0.1 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.14 in precipitation 0.1 SepOctober: 0.65 in precipitation 0.7 OctNovember: 0.95 in precipitation 0.9 NovDecember: 1.86 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Rancho Bernardo, CA (6 mi away); precipitation: Encinitas 3.34ene, CA (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

1 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

9206710a
Rancho Santa Fe, CA · 2 mi
9202910a
Escondido, CA · 4 mi
9212710a
San Diego, CA · 4 mi
9202410a
Encinitas, CA · 4 mi
9207810a
San Marcos, CA · 4 mi
9200910a
Carlsbad, CA · 5 mi
9209610a
San Marcos, CA · 5 mi
9200710b
Cardiff By The Sea, CA · 6 mi

All 2 ZIP codes in Rancho Santa Fe → · California planting zones →

Questions about 92091

What planting zone is ZIP code 92091?

ZIP code 92091 (Rancho Santa Fe, CA) is in USDA hardiness zone 10a on the 2023 map: the coldest night of an average winter reaches 30 to 35 °F (−1.1 to 1.7 °C).

How much rain and snow does 92091 get?

About 12.6 inches of precipitation a year (NOAA 1991–2020 normals, Encinitas 3.34ene station).

How hot do summers get in Rancho Santa Fe, CA?

The average high peaks at 83 °F in August, with about 21 days a year at 90 °F or more.

What kind of soil does 92091 have?

The USDA soil survey maps Huerhuero at the center of ZIP 92091: loam, moderately well drained, pH about 5.6 (moderately acidic).

Did spring come early in Rancho Santa Fe, CA in 2026?

Spring leaf-out near 92091 came on Jan 18 in 2026, 4 days earlier than the 1991–2020 average (Jan 22), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Rancho Santa Fe, CA?

Intermediate onions: the longest day near 92091 is 14 h 20 min, so day-neutral types bulb best; long-day varieties may not bulb fully.