Planting zone for 94063 — Redwood City, CA
ZIP code 94063 (Redwood City, San Mateo County) is in USDA zone 10a: the coldest winter night averages 30 to 35 °F.
Where ZIP 94063 is
Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading 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
A 32 °F frost doesn't happen here in most winters. At the nearest station (NOAA station Redwood City, CA — 2 miles away, elevation 30 ft) the median growing season is 333 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 94063 came on Jan 27 — about the same time as the 1991–2020 average (Jan 28).
Jan 282026
Jan 27
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 94063 is Novato — clay, very poorly drained.
Map unit: Novato clay, 0 to 1 percent slopes ponded.
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 94063; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Redwood City, CA
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Redwood City, CA (2 mi away); precipitation: Redwood City, CA (2 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
5 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.
All 5 ZIP codes in Redwood City → · California planting zones →
Questions about 94063
What planting zone is ZIP code 94063?
ZIP code 94063 (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).
How much rain and snow does 94063 get?
About 19 inches of precipitation a year (NOAA 1991–2020 normals, Redwood City station).
How hot do summers get in Redwood City, CA?
The average high peaks at 81 °F in July, with about 18 days a year at 90 °F or more.
What kind of soil does 94063 have?
The USDA soil survey maps Novato at the center of ZIP 94063: clay, very poorly drained, pH about 8.5 (alkaline).
Did spring come early in Redwood City, CA in 2026?
Spring leaf-out near 94063 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 Redwood City, CA?
Intermediate onions: the longest day near 94063 is 14 h 45 min, so day-neutral types bulb best; long-day varieties may not bulb fully.
Did the zone for 94063 change?
Yes. The 2012 USDA map put 94063 in zone 9b; the 2023 map puts it in zone 10a. The newer map uses 1991–2020 data and more weather stations.