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

Planting zone for 94064 — Redwood City, CA

ZIP code 94064 (Redwood City, San Mateo County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F. The median last spring frost is March 2 and the first fall frost November 25.

Where ZIP 94064 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 frostMar 2
First frostNov 25
2012 zone9b

Was 9b on the 2012 map — half a zone warmer now. 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 Redwood City, 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 Redwood City, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 2median — 50% chance of a later frost
Safe for tender plantsApril 15only 10% chance of frost after
First fall frostNovember 25median — 10% chance by Nov 1
Growing season268 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 2 and returns around December 12.

From the NOAA station San Gregorio 2 Se, CA — 5 miles away, elevation 276 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 94064

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 19 – Feb 2
SpinachSow outdoors · Jan 19 – Feb 9
Broccoli, cabbageStart indoors · Dec 22 – Jan 5
Broccoli, cabbageTransplant · Feb 9 – Feb 23
Onion setsPlant outdoors · Feb 2 – Feb 16
PotatoesPlant outdoors · Feb 9 – Feb 23
LettuceSow outdoors · Feb 2 – Feb 16
Carrots, beetsSow outdoors · Feb 9 – Feb 23
TomatoesStart indoors · Jan 5 – Jan 19
TomatoesTransplant · Mar 9 – Mar 23
Peppers, eggplantStart indoors · Dec 22 – Jan 5
Peppers, eggplantTransplant · Mar 16 – Mar 30
BeansSow outdoors · Mar 9 – Mar 23
Sweet cornSow outdoors · Mar 9 – Mar 23
Cucumbers, squashSow outdoors · Mar 9 – Mar 23
Fall lettuce, spinachSow outdoors · Sep 30 – Oct 14
GarlicPlant cloves · Nov 11 – Dec 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 2) and first fall frost (Nov 25) 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 94064 came on Jan 18 — 9 days earlier than the 1991–2020 average (Jan 27).

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 Redwood City, CA

The soil mapped at the center of ZIP 94064 is Sweeney — clay loam, well drained.

TextureClay loamholds water and nutrients; slow to drain and warm up
pH6.3slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.5%moderate
Hydrologic groupBwater soaks in moderately
Farmland classNot prime farmlandUSDA classification

Map unit: Sweeney clay loam, moderately steep, eroded.

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 94064; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Redwood City, CA

Summer high72 °Faverage high, September
Winter low40 °Faverage low, January
Hot days2days a year at 90 °F or more
Freezing nights16nights a year at 32 °F or less
Growing degree days2,010base 50 °F — the season’s usable heat
Longest day14 h 44 mindaylight on June 21
Shortest day9 h 35 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation43.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°32 °FJanuary: average high 60 °F, low 40 °F 60°40° JanFebruary: average high 60 °F, low 41 °F 60°41° FebMarch: average high 61 °F, low 42 °F 61°42° MarApril: average high 62 °F, low 43 °F 62°43° AprMay: average high 64 °F, low 46 °F 64°46° MayJune: average high 67 °F, low 48 °F 67°48° JunJuly: average high 69 °F, low 52 °F 69°52° JulAugust: average high 71 °F, low 52 °F 71°52° AugSeptember: average high 72 °F, low 49 °F 72°49° SepOctober: average high 69 °F, low 45 °F 69°45° OctNovember: average high 63 °F, low 41 °F 63°41° NovDecember: average high 59 °F, low 40 °F 59°40° Dec

Precipitation by month inches

0″2″4″6″8″January: 7.37 in precipitation 7.4 JanFebruary: 7.36 in precipitation 7.4 FebMarch: 7.68 in precipitation 7.7 MarApril: 3.64 in precipitation 3.6 AprMay: 1.64 in precipitation 1.6 MayJune: 0.68 in precipitation 0.7 JunJuly: 0.01 in precipitation 0.0 JulAugust: 0.05 in precipitation 0.1 AugSeptember: 0.12 in precipitation 0.1 SepOctober: 2.06 in precipitation 2.1 OctNovember: 4.48 in precipitation 4.5 NovDecember: 8.53 in precipitation 8.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: San Gregorio 2 Se, CA (5 mi away); precipitation: Woodside 3.4 S, CA (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

940269b
Menlo Park, CA · <1 mi
940749b
San Gregorio, CA · 3 mi
9406210a
Redwood City, CA · 4 mi
9401910a
Half Moon Bay, CA · 7 mi
940289b
Portola Valley, CA · 7 mi
9406110a
Redwood City, CA · 8 mi
9407010a
San Carlos, CA · 9 mi
940279b
Atherton, CA · 9 mi

All 5 ZIP codes in Redwood City → · California planting zones →

Questions about 94064

What planting zone is ZIP code 94064?

ZIP code 94064 (Redwood City, 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).

When is the last frost in Redwood City, CA?

The median last spring frost (32 °F) near 94064 is March 2; after April 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, San Gregorio 2 Se station.

When is the first frost in Redwood City, CA?

The median first fall frost near 94064 is November 25, giving a median frost-free growing season of 268 days.

When should I plant tomatoes in 94064?

Start tomato seeds indoors around Jan 5 – Jan 19 and set transplants outside around Mar 9 – Mar 23, one to three weeks after the median last frost.

How much rain and snow does 94064 get?

About 43.6 inches of precipitation a year (NOAA 1991–2020 normals, Woodside 3.4 S station).

How hot do summers get in Redwood City, CA?

The average high peaks at 72 °F in September, with about 2 days a year at 90 °F or more.

What kind of soil does 94064 have?

The USDA soil survey maps Sweeney at the center of ZIP 94064: clay loam, well drained, pH about 6.3 (slightly acidic).

Did spring come early in Redwood City, CA in 2026?

Spring leaf-out near 94064 came on Jan 18 in 2026, 9 days earlier than the 1991–2020 average (Jan 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Redwood City, CA?

Intermediate onions: the longest day near 94064 is 14 h 44 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 94064 change?

Yes. The 2012 USDA map put 94064 in zone 9b; the 2023 map puts it in zone 10a. The newer map uses 1991–2020 data and more weather stations.