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

Planting zone for 92070 — Santa Ysabel, CA

ZIP code 92070 (Santa Ysabel, San Diego County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is April 18 and the first fall frost October 26.

Where ZIP 92070 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostApr 18
First frostOct 26
2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Santa Ysabel, 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 Santa Ysabel, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 18median — 50% chance of a later frost
Safe for tender plantsMay 14only 10% chance of frost after
First fall frostOctober 26median — 10% chance by Oct 9
Growing season189 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 14 and returns around November 14.

From the NOAA station Henshaw Dam, CA — 4 miles away, elevation 2,700 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 92070

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 7 – Mar 21
SpinachSow outdoors · Mar 7 – Mar 28
Broccoli, cabbageStart indoors · Feb 7 – Feb 21
Broccoli, cabbageTransplant · Mar 28 – Apr 11
Onion setsPlant outdoors · Mar 21 – Apr 4
PotatoesPlant outdoors · Mar 28 – Apr 11
LettuceSow outdoors · Mar 21 – Apr 4
Carrots, beetsSow outdoors · Mar 28 – Apr 11
TomatoesStart indoors · Feb 21 – Mar 7
TomatoesTransplant · Apr 25 – May 9
Peppers, eggplantStart indoors · Feb 7 – Feb 21
Peppers, eggplantTransplant · May 2 – May 16
BeansSow outdoors · Apr 25 – May 9
Sweet cornSow outdoors · Apr 25 – May 9
Cucumbers, squashSow outdoors · Apr 25 – May 9
Fall lettuce, spinachSow outdoors · Aug 31 – Sep 14
GarlicPlant cloves · Oct 12 – Nov 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 26) 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 92070 came on Jan 20 — 14 days earlier than the 1991–2020 average (Feb 3).

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 Santa Ysabel, CA

The soil mapped at the center of ZIP 92070 is Sheephead — sandy loam, well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Sheephead sandy loam, 9 to 30 percent slopes, stony.

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 92070; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Santa Ysabel, CA

Summer high94 °Faverage high, August
Winter low30 °Faverage low, December
Hot days88days a year at 90 °F or more
Freezing nights105nights a year at 32 °F or less
Growing degree days3,418base 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
Precipitation25.2 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 61 °F, low 31 °F 61°31° JanFebruary: average high 61 °F, low 32 °F 61°32° FebMarch: average high 65 °F, low 35 °F 65°35° MarApril: average high 69 °F, low 38 °F 69°38° AprMay: average high 75 °F, low 43 °F 75°43° MayJune: average high 85 °F, low 46 °F 85°46° JunJuly: average high 92 °F, low 53 °F 92°53° JulAugust: average high 94 °F, low 54 °F 94°54° AugSeptember: average high 89 °F, low 49 °F 89°49° SepOctober: average high 79 °F, low 40 °F 79°40° OctNovember: average high 69 °F, low 34 °F 69°34° NovDecember: average high 60 °F, low 30 °F 60°30° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.26 in precipitation 5.3 JanFebruary: 5.88 in precipitation 5.9 FebMarch: 4.09 in precipitation 4.1 MarApril: 1.73 in precipitation 1.7 AprMay: 0.70 in precipitation 0.7 MayJune: 0.11 in precipitation 0.1 JunJuly: 0.18 in precipitation 0.2 JulAugust: 0.29 in precipitation 0.3 AugSeptember: 0.44 in precipitation 0.4 SepOctober: 0.93 in precipitation 0.9 OctNovember: 1.87 in precipitation 1.9 NovDecember: 3.75 in precipitation 3.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Henshaw Dam, CA (4 mi away); precipitation: Henshaw Dam, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

920868b
Warner Springs, CA · 11 mi
9214310b
San Ysidro, CA · 11 mi
920659b
Ramona, CA · 11 mi
920669a
Ranchita, CA · 12 mi
920609a
Palomar Mountain, CA · 13 mi
920619b
Pauma Valley, CA · 13 mi
920279b
Escondido, CA · 14 mi
919169b
Descanso, CA · 20 mi

California planting zones →

Questions about 92070

What planting zone is ZIP code 92070?

ZIP code 92070 (Santa Ysabel, CA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Santa Ysabel, CA?

The median last spring frost (32 °F) near 92070 is April 18; after May 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Henshaw Dam station.

When is the first frost in Santa Ysabel, CA?

The median first fall frost near 92070 is October 26, giving a median frost-free growing season of 189 days.

When should I plant tomatoes in 92070?

Start tomato seeds indoors around Feb 21 – Mar 7 and set transplants outside around Apr 25 – May 9, one to three weeks after the median last frost.

How much rain and snow does 92070 get?

About 25.2 inches of precipitation a year (NOAA 1991–2020 normals, Henshaw Dam station).

How hot do summers get in Santa Ysabel, CA?

The average high peaks at 94 °F in August, with about 88 days a year at 90 °F or more.

What kind of soil does 92070 have?

The USDA soil survey maps Sheephead at the center of ZIP 92070: sandy loam, well drained, pH about 6.5 (neutral).

Did spring come early in Santa Ysabel, CA in 2026?

Spring leaf-out near 92070 came on Jan 20 in 2026, 14 days earlier than the 1991–2020 average (Feb 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Santa Ysabel, CA?

Intermediate onions: the longest day near 92070 is 14 h 21 min, so day-neutral types bulb best; long-day varieties may not bulb fully.