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

Planting zone for 92840 — Garden Grove, CA

ZIP code 92840 (Garden Grove, Orange County) is in USDA zone 10b: the coldest winter night averages 35 to 40 °F.

Where ZIP 92840 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.

Zone10b35 to 40 °F
Coldest night1.7 to 4.4 °C
Last frostrare
First frostrare
2012 zone10b

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 10b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Garden Grove, 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 Tustin Irvine Rch, CA — 12 miles away, elevation 236 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 92840 came on Jan 17 — 4 days earlier than the 1991–2020 average (Jan 21).

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 Garden Grove, CA

The soil mapped at the center of ZIP 92840 is Hueneme — fine sandy loam, poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding
pH7.9alkaline; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter0.75%low — add compost
Hydrologic groupAwater soaks in fast
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Hueneme fine sandy loam, drained.

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 92840; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Garden Grove, CA

Summer high85 °Faverage high, August
Winter low48 °Faverage low, December
Hot days30days a year at 90 °F or more
Freezing nights0nights a year at 32 °F or less
Growing degree days5,886base 50 °F — the season’s usable heat
Longest day14 h 24 mindaylight on June 21
Shortest day9 h 54 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation12.5 inper year, rain and melted snow

Average high and low, by month

40°50°60°70°80°90°100°January: average high 69 °F, low 49 °F 69°49° JanFebruary: average high 69 °F, low 50 °F 69°50° FebMarch: average high 71 °F, low 52 °F 71°52° MarApril: average high 73 °F, low 54 °F 73°54° AprMay: average high 75 °F, low 58 °F 75°58° MayJune: average high 78 °F, low 61 °F 78°61° JunJuly: average high 83 °F, low 65 °F 83°65° JulAugust: average high 85 °F, low 65 °F 85°65° AugSeptember: average high 84 °F, low 64 °F 84°64° SepOctober: average high 79 °F, low 59 °F 79°59° OctNovember: average high 74 °F, low 53 °F 74°53° NovDecember: average high 68 °F, low 48 °F 68°48° Dec

Precipitation by month inches

0″1″2″3″4″January: 2.88 in precipitation 2.9 JanFebruary: 3.16 in precipitation 3.2 FebMarch: 1.71 in precipitation 1.7 MarApril: 0.82 in precipitation 0.8 AprMay: 0.29 in precipitation 0.3 MayJune: 0.08 in precipitation 0.1 JunJuly: 0.03 in precipitation 0.0 JulAugust: 0.00 in precipitation 0.0 AugSeptember: 0.12 in precipitation 0.1 SepOctober: 0.50 in precipitation 0.5 OctNovember: 0.79 in precipitation 0.8 NovDecember: 2.16 in precipitation 2.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Santa Ana Fire Stn, CA (5 mi away); precipitation: Santa Ana Fire Stn, CA (5 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9284210b
Garden Grove, CA · <1 mi
9280210b
Anaheim, CA · 2 mi
9284310b
Garden Grove, CA · 2 mi
9281210b
Anaheim, CA · 2 mi
9284410b
Garden Grove, CA · 3 mi
9281410a
Anaheim, CA · 3 mi
9284110a
Garden Grove, CA · 3 mi
9270310b
Santa Ana, CA · 3 mi

All 7 ZIP codes in Garden Grove → · California planting zones →

Questions about 92840

What planting zone is ZIP code 92840?

ZIP code 92840 (Garden Grove, CA) is in USDA hardiness zone 10b on the 2023 map: the coldest night of an average winter reaches 35 to 40 °F (1.7 to 4.4 °C).

How much rain and snow does 92840 get?

About 12.5 inches of precipitation a year (NOAA 1991–2020 normals, Santa Ana Fire Stn station).

How hot do summers get in Garden Grove, CA?

The average high peaks at 85 °F in August, with about 30 days a year at 90 °F or more.

What kind of soil does 92840 have?

The USDA soil survey maps Hueneme at the center of ZIP 92840: fine sandy loam, poorly drained, pH about 7.9 (alkaline).

Did spring come early in Garden Grove, CA in 2026?

Spring leaf-out near 92840 came on Jan 17 in 2026, 4 days earlier than the 1991–2020 average (Jan 21), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Garden Grove, CA?

Intermediate onions: the longest day near 92840 is 14 h 24 min, so day-neutral types bulb best; long-day varieties may not bulb fully.