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

Planting zone for 94019 — Half Moon Bay, CA

ZIP code 94019 (Half Moon Bay, San Mateo County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F. The median last spring frost is February 6 and the first fall frost December 17.

Where ZIP 94019 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.

Zone10a30 to 35 °F
Coldest night−1.1 to 1.7 °C
Last frostFeb 6
First frostDec 17
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 Half Moon Bay, 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 Half Moon Bay, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 6median — 50% chance of a later frost
Safe for tender plantsMarch 25only 10% chance of frost after
First fall frostDecember 17median — 10% chance by Nov 25
Growing season328 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 5 and returns around December 31.

From the NOAA station Half Moon Bay, CA — 2 miles away, elevation 26 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 94019

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 26 – Jan 9
SpinachSow outdoors · Dec 26 – Jan 16
Broccoli, cabbageStart indoors · Nov 28 – Dec 12
Broccoli, cabbageTransplant · Jan 16 – Jan 30
Onion setsPlant outdoors · Jan 9 – Jan 23
PotatoesPlant outdoors · Jan 16 – Jan 30
LettuceSow outdoors · Jan 9 – Jan 23
Carrots, beetsSow outdoors · Jan 16 – Jan 30
TomatoesStart indoors · Dec 12 – Dec 26
TomatoesTransplant · Feb 13 – Feb 27
Peppers, eggplantStart indoors · Nov 28 – Dec 12
Peppers, eggplantTransplant · Feb 20 – Mar 6
BeansSow outdoors · Feb 13 – Feb 27
Sweet cornSow outdoors · Feb 13 – Feb 27
Cucumbers, squashSow outdoors · Feb 13 – Feb 27
Fall lettuce, spinachSow outdoors · Oct 22 – Nov 5
GarlicPlant cloves · Dec 3 – Jan 7
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 6) and first fall frost (Dec 17) 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 94019 came on Jan 26 — about the same time as the 1991–2020 average (Jan 26).

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 Half Moon Bay, CA

The soil mapped at the center of ZIP 94019 is Tierra — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH5.3strongly acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter0.7%low — add compost
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Gullied land (Tierra and Watsonville soil materials).

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 94019; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Half Moon Bay, CA

Summer high66 °Faverage high, August
Winter low43 °Faverage low, January
Hot days1days a year at 90 °F or more
Freezing nights5nights a year at 32 °F or less
Growing degree days1,952base 50 °F — the season’s usable heat
Longest day14 h 45 mindaylight on June 21
Shortest day9 h 34 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation24.6 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°32 °FJanuary: average high 59 °F, low 43 °F 59°43° JanFebruary: average high 60 °F, low 43 °F 60°43° FebMarch: average high 60 °F, low 44 °F 60°44° MarApril: average high 61 °F, low 45 °F 61°45° AprMay: average high 62 °F, low 48 °F 62°48° MayJune: average high 64 °F, low 50 °F 64°50° JunJuly: average high 65 °F, low 53 °F 65°53° JulAugust: average high 66 °F, low 54 °F 66°54° AugSeptember: average high 66 °F, low 51 °F 66°51° SepOctober: average high 66 °F, low 48 °F 66°48° OctNovember: average high 63 °F, low 45 °F 63°45° NovDecember: average high 59 °F, low 43 °F 59°43° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 4.51 in precipitation 4.5 JanFebruary: 4.09 in precipitation 4.1 FebMarch: 3.37 in precipitation 3.4 MarApril: 1.88 in precipitation 1.9 AprMay: 0.98 in precipitation 1.0 MayJune: 0.43 in precipitation 0.4 JunJuly: 0.12 in precipitation 0.1 JulAugust: 0.35 in precipitation 0.3 AugSeptember: 0.14 in precipitation 0.1 SepOctober: 1.21 in precipitation 1.2 OctNovember: 2.63 in precipitation 2.6 NovDecember: 4.88 in precipitation 4.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Half Moon Bay, CA (2 mi away); precipitation: Half Moon Bay 0.5 Ssw, CA (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

9401810a
El Granada, CA · 5 mi
940269b
Menlo Park, CA · 7 mi
9406410a
Redwood City, CA · 7 mi
9403810a
Moss Beach, CA · 7 mi
9449710a
San Mateo, CA · 7 mi
9406210a
Redwood City, CA · 7 mi
9440210a
San Mateo, CA · 7 mi
9400210a
Belmont, CA · 7 mi

California planting zones →

Questions about 94019

What planting zone is ZIP code 94019?

ZIP code 94019 (Half Moon Bay, 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 Half Moon Bay, CA?

The median last spring frost (32 °F) near 94019 is February 6; after March 25 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Half Moon Bay station.

When is the first frost in Half Moon Bay, CA?

The median first fall frost near 94019 is December 17, giving a median frost-free growing season of 328 days.

When should I plant tomatoes in 94019?

Start tomato seeds indoors around Dec 12 – Dec 26 and set transplants outside around Feb 13 – Feb 27, one to three weeks after the median last frost.

How much rain and snow does 94019 get?

About 24.6 inches of precipitation a year (NOAA 1991–2020 normals, Half Moon Bay 0.5 Ssw station).

How hot do summers get in Half Moon Bay, CA?

The average high peaks at 66 °F in August, with about 1 days a year at 90 °F or more.

What kind of soil does 94019 have?

The USDA soil survey maps Tierra at the center of ZIP 94019: loam, moderately well drained, pH about 5.3 (strongly acidic).

Did spring come early in Half Moon Bay, CA in 2026?

Spring leaf-out near 94019 came on Jan 26 in 2026, about the same as the 1991–2020 average (Jan 26), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Half Moon Bay, CA?

Intermediate onions: the longest day near 94019 is 14 h 45 min, so day-neutral types bulb best; long-day varieties may not bulb fully.