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

Planting zone for 92022 — El Cajon, CA

ZIP code 92022 (El Cajon, San Diego County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.

Where ZIP 92022 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.

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 El Cajon, 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 El Cajon, CA — 2 miles away, elevation 495 ft) the median growing season is 350 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 92022 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 El Cajon, CA

The soil mapped at the center of ZIP 92022 is Placentia — sandy loam, moderately well drained.

TextureSandy loamdrains and warms fast; dries out and needs more feeding
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.25%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Placentia sandy loam, thick surface, 2 to 9 percent slo pes.

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 92022; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in El Cajon, CA

Summer high89 °Faverage high, August
Winter low42 °Faverage low, December
Hot days57days a year at 90 °F or more
Freezing nights3nights a year at 32 °F or less
Growing degree days5,564base 50 °F — the season’s usable heat
Longest day14 h 19 mindaylight on June 21
Shortest day9 h 59 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation13.5 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 69 °F, low 43 °F 69°43° JanFebruary: average high 69 °F, low 44 °F 69°44° FebMarch: average high 71 °F, low 48 °F 71°48° MarApril: average high 75 °F, low 51 °F 75°51° AprMay: average high 76 °F, low 56 °F 76°56° MayJune: average high 81 °F, low 59 °F 81°59° JunJuly: average high 86 °F, low 63 °F 86°63° JulAugust: average high 89 °F, low 65 °F 89°65° AugSeptember: average high 87 °F, low 62 °F 87°62° SepOctober: average high 81 °F, low 56 °F 81°56° OctNovember: average high 75 °F, low 47 °F 75°47° NovDecember: average high 69 °F, low 42 °F 69°42° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.68 in precipitation 2.7 JanFebruary: 3.82 in precipitation 3.8 FebMarch: 1.21 in precipitation 1.2 MarApril: 0.88 in precipitation 0.9 AprMay: 0.39 in precipitation 0.4 MayJune: 0.13 in precipitation 0.1 JunJuly: 0.06 in precipitation 0.1 JulAugust: 0.02 in precipitation 0.0 AugSeptember: 0.15 in precipitation 0.1 SepOctober: 0.57 in precipitation 0.6 OctNovember: 0.92 in precipitation 0.9 NovDecember: 2.65 in precipitation 2.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: El Cajon, CA (2 mi away); precipitation: El Cajon 1.5wsw, CA (within 1 mile). 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.

9202010a
El Cajon, CA · <1 mi
9207210a
Santee, CA · 3 mi
9194110b
La Mesa, CA · 3 mi
9194210b
La Mesa, CA · 4 mi
9194310b
La Mesa, CA · 4 mi
9194410b
La Mesa, CA · 4 mi
9197610b
Spring Valley, CA · 4 mi
9197910b
Spring Valley, CA · 4 mi

All 4 ZIP codes in El Cajon → · California planting zones →

Questions about 92022

What planting zone is ZIP code 92022?

ZIP code 92022 (El Cajon, 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 92022 get?

About 13.5 inches of precipitation a year (NOAA 1991–2020 normals, El Cajon 1.5wsw station).

How hot do summers get in El Cajon, CA?

The average high peaks at 89 °F in August, with about 57 days a year at 90 °F or more.

What kind of soil does 92022 have?

The USDA soil survey maps Placentia at the center of ZIP 92022: sandy loam, moderately well drained, pH about 6.1 (slightly acidic).

Did spring come early in El Cajon, CA in 2026?

Spring leaf-out near 92022 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 El Cajon, CA?

Intermediate onions: the longest day near 92022 is 14 h 19 min, so day-neutral types bulb best; long-day varieties may not bulb fully.