Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 92068 — San Luis Rey, CA

ZIP code 92068 (San Luis Rey, San Diego County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 23 and the first fall frost December 11.

Where ZIP 92068 is

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.

Zone9b25 to 30 °F

Coldest night−3.9 to −1.1 °C

Last frostJan 23

First frostDec 11

2012 zone10a

Was 10a on the 2012 map — half a zone colder now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for San Luis Rey, 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 in San Luis Rey, CA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostJanuary 23median — 50% chance of a later frost

Safe for tender plantsFebruary 22only 10% chance of frost after

First fall frostDecember 11median — 10% chance by Nov 21

Growing season325 daysfrost-free, median

A hard freeze (28 °F) usually ends around December 31 and returns around December 23.

From the NOAA station Oceanside Municipal Airport, CA — 2 miles away, elevation 30 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 92068

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 12 – Dec 26

SpinachSow outdoors · Dec 12 – Jan 2

Broccoli, cabbageStart indoors · Nov 14 – Nov 28

Broccoli, cabbageTransplant · Jan 2 – Jan 16

Onion setsPlant outdoors · Dec 26 – Jan 9

PotatoesPlant outdoors · Jan 2 – Jan 16

LettuceSow outdoors · Dec 26 – Jan 9

Carrots, beetsSow outdoors · Jan 2 – Jan 16

TomatoesStart indoors · Nov 28 – Dec 12

TomatoesTransplant · Jan 30 – Feb 13

Peppers, eggplantStart indoors · Nov 14 – Nov 28

Peppers, eggplantTransplant · Feb 6 – Feb 20

BeansSow outdoors · Jan 30 – Feb 13

Sweet cornSow outdoors · Jan 30 – Feb 13

Cucumbers, squashSow outdoors · Jan 30 – Feb 13

Fall lettuce, spinachSow outdoors · Oct 16 – Oct 30

GarlicPlant cloves · Nov 27 – Jan 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 23) and first fall frost (Dec 11) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 92068 came on Jan 19 — 4 days earlier than the 1991–2020 average (Jan 23).

average
Jan 232026
Jan 19

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 San Luis Rey, CA

The soil mapped at the center of ZIP 92068 is Grangeville — fine sandy loam, somewhat poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

pH8.2alkaline; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter3.5%moderate

Hydrologic groupBwater soaks in moderately

Farmland classPrime farmland if irrigated and drainedUSDA classification

Map unit: Grangeville fine sandy loam, 0 to 2 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 92068; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in San Luis Rey, CA

Summer high78 °Faverage high, August

Winter low40 °Faverage low, December

Hot days5days a year at 90 °F or more

Freezing nights8nights a year at 32 °F or less

Growing degree days4,072base 50 °F — the season’s usable heat

Longest day14 h 21 mindaylight on June 21

Shortest day9 h 57 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation11.9 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oceanside Municipal Airport, CA (2 mi away); precipitation: Oceanside Municipal Airport, CA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

California planting zones →

Questions about 92068

What planting zone is ZIP code 92068?

ZIP code 92068 (San Luis Rey, CA) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in San Luis Rey, CA?

The median last spring frost (32 °F) near 92068 is January 23; after February 22 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Oceanside Municipal Airport station.

When is the first frost in San Luis Rey, CA?

The median first fall frost near 92068 is December 11, giving a median frost-free growing season of 325 days.

When should I plant tomatoes in 92068?

Start tomato seeds indoors around Nov 28 – Dec 12 and set transplants outside around Jan 30 – Feb 13, one to three weeks after the median last frost.

How much rain and snow does 92068 get?

About 11.9 inches of precipitation a year (NOAA 1991–2020 normals, Oceanside Municipal Airport station).

How hot do summers get in San Luis Rey, CA?

The average high peaks at 78 °F in August, with about 5 days a year at 90 °F or more.

What kind of soil does 92068 have?

The USDA soil survey maps Grangeville at the center of ZIP 92068: fine sandy loam, somewhat poorly drained, pH about 8.2 (alkaline).

Did spring come early in San Luis Rey, CA in 2026?

Spring leaf-out near 92068 came on Jan 19 in 2026, 4 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in San Luis Rey, CA?

Intermediate onions: the longest day near 92068 is 14 h 21 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 92068 change?

Yes. The 2012 USDA map put 92068 in zone 10a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.