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

Planting zone for 93220 — Edison, CA

ZIP code 93220 (Edison, Kern County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 31 and the first fall frost December 8.

Where ZIP 93220 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.

Zone9b25 to 30 °F
Coldest night−3.9 to −1.1 °C
Last frostJan 31
First frostDec 8
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 Edison, 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 Edison, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJanuary 31median — 50% chance of a later frost
Safe for tender plantsFebruary 27only 10% chance of frost after
First fall frostDecember 8median — 10% chance by Nov 23
Growing season312 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 3 and returns around December 20.

From the NOAA station Bakersfield 5 Nw, CA — 16 miles away, elevation 469 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 93220

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 20 – Jan 3
SpinachSow outdoors · Dec 20 – Jan 10
Broccoli, cabbageStart indoors · Nov 22 – Dec 6
Broccoli, cabbageTransplant · Jan 10 – Jan 24
Onion setsPlant outdoors · Jan 3 – Jan 17
PotatoesPlant outdoors · Jan 10 – Jan 24
LettuceSow outdoors · Jan 3 – Jan 17
Carrots, beetsSow outdoors · Jan 10 – Jan 24
TomatoesStart indoors · Dec 6 – Dec 20
TomatoesTransplant · Feb 7 – Feb 21
Peppers, eggplantStart indoors · Nov 22 – Dec 6
Peppers, eggplantTransplant · Feb 14 – Feb 28
BeansSow outdoors · Feb 7 – Feb 21
Sweet cornSow outdoors · Feb 7 – Feb 21
Cucumbers, squashSow outdoors · Feb 7 – Feb 21
Fall lettuce, spinachSow outdoors · Oct 13 – Oct 27
GarlicPlant cloves · Nov 24 – Dec 29
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 31) and first fall frost (Dec 8) 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 93220 came on Jan 27 — about the same time as the 1991–2020 average (Jan 28).

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 Edison, CA

The soil mapped at the center of ZIP 93220 is Xeric Torriorthents — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH8.0alkaline; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter0.4%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Xeric Torriorthents-Calcic Haploxerepts association, 15 to 60 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 93220; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Edison, CA

Summer high97 °Faverage high, July
Winter low38 °Faverage low, December
Hot days110days a year at 90 °F or more
Freezing nights17nights a year at 32 °F or less
Growing degree days5,799base 50 °F — the season’s usable heat
Longest day14 h 33 mindaylight on June 21
Shortest day9 h 46 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation6.7 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 58 °F, low 39 °F 58°39° JanFebruary: average high 64 °F, low 41 °F 64°41° FebMarch: average high 69 °F, low 45 °F 69°45° MarApril: average high 75 °F, low 49 °F 75°49° AprMay: average high 83 °F, low 57 °F 83°57° MayJune: average high 91 °F, low 64 °F 91°64° JunJuly: average high 97 °F, low 70 °F 97°70° JulAugust: average high 96 °F, low 69 °F 96°69° AugSeptember: average high 91 °F, low 64 °F 91°64° SepOctober: average high 80 °F, low 54 °F 80°54° OctNovember: average high 67 °F, low 44 °F 67°44° NovDecember: average high 59 °F, low 38 °F 59°38° Dec

Precipitation by month inches

0″1″2″January: 1.27 in precipitation 1.3 JanFebruary: 1.28 in precipitation 1.3 FebMarch: 1.24 in precipitation 1.2 MarApril: 0.62 in precipitation 0.6 AprMay: 0.32 in precipitation 0.3 MayJune: 0.01 in precipitation 0.0 JunJuly: 0.02 in precipitation 0.0 JulAugust: 0.00 in precipitation 0.0 AugSeptember: 0.11 in precipitation 0.1 SepOctober: 0.22 in precipitation 0.2 OctNovember: 0.53 in precipitation 0.5 NovDecember: 1.03 in precipitation 1.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Bakersfield 5 Nw, CA (16 mi away); precipitation: Bakersfield 5 Nw, CA (16 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

933069b
Bakersfield, CA · 6 mi
933039b
Bakersfield, CA · 9 mi
933809b
Bakersfield, CA · 9 mi
933839b
Bakersfield, CA · 9 mi
933859b
Bakersfield, CA · 9 mi
933869b
Bakersfield, CA · 9 mi
933879b
Bakersfield, CA · 9 mi
933889b
Bakersfield, CA · 9 mi

California planting zones →

Questions about 93220

What planting zone is ZIP code 93220?

ZIP code 93220 (Edison, 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 Edison, CA?

The median last spring frost (32 °F) near 93220 is January 31; after February 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Bakersfield 5 Nw station.

When is the first frost in Edison, CA?

The median first fall frost near 93220 is December 8, giving a median frost-free growing season of 312 days.

When should I plant tomatoes in 93220?

Start tomato seeds indoors around Dec 6 – Dec 20 and set transplants outside around Feb 7 – Feb 21, one to three weeks after the median last frost.

How much rain and snow does 93220 get?

About 6.7 inches of precipitation a year (NOAA 1991–2020 normals, Bakersfield 5 Nw station).

How hot do summers get in Edison, CA?

The average high peaks at 97 °F in July, with about 110 days a year at 90 °F or more.

What kind of soil does 93220 have?

The USDA soil survey maps Xeric Torriorthents at the center of ZIP 93220: silt loam, well drained, pH about 8.0 (alkaline).

Did spring come early in Edison, CA in 2026?

Spring leaf-out near 93220 came on Jan 27 in 2026, about the same as the 1991–2020 average (Jan 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Edison, CA?

Intermediate onions: the longest day near 93220 is 14 h 33 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 93220 change?

Yes. The 2012 USDA map put 93220 in zone 10a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.