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

Planting zone for 95406 — Santa Rosa, CA

ZIP code 95406 (Santa Rosa, Sonoma County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 25 and the first fall frost December 1.

Where ZIP 95406 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostFeb 25
First frostDec 1
2012 zone9b

Was 9b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Santa Rosa, 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 Santa Rosa, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 25median — 50% chance of a later frost
Safe for tender plantsMarch 29only 10% chance of frost after
First fall frostDecember 1median — 10% chance by Nov 10
Growing season279 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 20 and returns around December 16.

From the NOAA station Santa Rosa, CA — within 1 mile, elevation 167 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 95406

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 14 – Jan 28
SpinachSow outdoors · Jan 14 – Feb 4
Broccoli, cabbageStart indoors · Dec 17 – Dec 31
Broccoli, cabbageTransplant · Feb 4 – Feb 18
Onion setsPlant outdoors · Jan 28 – Feb 11
PotatoesPlant outdoors · Feb 4 – Feb 18
LettuceSow outdoors · Jan 28 – Feb 11
Carrots, beetsSow outdoors · Feb 4 – Feb 18
TomatoesStart indoors · Dec 31 – Jan 14
TomatoesTransplant · Mar 4 – Mar 18
Peppers, eggplantStart indoors · Dec 17 – Dec 31
Peppers, eggplantTransplant · Mar 11 – Mar 25
BeansSow outdoors · Mar 4 – Mar 18
Sweet cornSow outdoors · Mar 4 – Mar 18
Cucumbers, squashSow outdoors · Mar 4 – Mar 18
Fall lettuce, spinachSow outdoors · Oct 6 – Oct 20
GarlicPlant cloves · Nov 17 – Dec 22
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 25) and first fall frost (Dec 1) 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 95406 came on Jan 29 — about the same time as the 1991–2020 average (Jan 30).

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 Santa Rosa, CA

The soil mapped at the center of ZIP 95406 is Yolo — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.4%moderate
Hydrologic groupBwater soaks in moderately
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Yolo silt loam, 0 to 5 percent slopes, MLRA 14.

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 95406; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Santa Rosa, CA

Summer high84 °Faverage high, September
Winter low38 °Faverage low, January
Hot days26days a year at 90 °F or more
Freezing nights15nights a year at 32 °F or less
Growing degree days3,509base 50 °F — the season’s usable heat
Longest day14 h 51 mindaylight on June 21
Shortest day9 h 29 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation31.5 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°32 °FJanuary: average high 60 °F, low 38 °F 60°38° JanFebruary: average high 64 °F, low 40 °F 64°40° FebMarch: average high 67 °F, low 42 °F 67°42° MarApril: average high 71 °F, low 44 °F 71°44° AprMay: average high 75 °F, low 48 °F 75°48° MayJune: average high 80 °F, low 51 °F 80°51° JunJuly: average high 82 °F, low 52 °F 82°52° JulAugust: average high 83 °F, low 53 °F 83°53° AugSeptember: average high 84 °F, low 51 °F 84°51° SepOctober: average high 79 °F, low 48 °F 79°48° OctNovember: average high 67 °F, low 42 °F 67°42° NovDecember: average high 59 °F, low 38 °F 59°38° Dec

Precipitation by month inches

0″2″4″6″January: 5.78 in precipitation 5.8 JanFebruary: 6.39 in precipitation 6.4 FebMarch: 4.26 in precipitation 4.3 MarApril: 1.98 in precipitation 2.0 AprMay: 1.28 in precipitation 1.3 MayJune: 0.29 in precipitation 0.3 JunJuly: 0.01 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.15 in precipitation 0.1 SepOctober: 1.63 in precipitation 1.6 OctNovember: 3.25 in precipitation 3.3 NovDecember: 6.47 in precipitation 6.5 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Santa Rosa, CA (within 1 mile); precipitation: Santa Rosa, CA (within 1 mile). 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.

954029b
Santa Rosa, CA · <1 mi
954059a
Santa Rosa, CA · 2 mi
954079a
Santa Rosa, CA · 4 mi
954019a
Santa Rosa, CA · 5 mi
954399a
Fulton, CA · 5 mi
954039a
Santa Rosa, CA · 5 mi
954049b
Santa Rosa, CA · 6 mi
949289a
Rohnert Park, CA · 7 mi

All 8 ZIP codes in Santa Rosa → · California planting zones →

Questions about 95406

What planting zone is ZIP code 95406?

ZIP code 95406 (Santa Rosa, CA) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Santa Rosa, CA?

The median last spring frost (32 °F) near 95406 is February 25; after March 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Santa Rosa station.

When is the first frost in Santa Rosa, CA?

The median first fall frost near 95406 is December 1, giving a median frost-free growing season of 279 days.

When should I plant tomatoes in 95406?

Start tomato seeds indoors around Dec 31 – Jan 14 and set transplants outside around Mar 4 – Mar 18, one to three weeks after the median last frost.

How much rain and snow does 95406 get?

About 31.5 inches of precipitation a year (NOAA 1991–2020 normals, Santa Rosa station).

How hot do summers get in Santa Rosa, CA?

The average high peaks at 84 °F in September, with about 26 days a year at 90 °F or more.

What kind of soil does 95406 have?

The USDA soil survey maps Yolo at the center of ZIP 95406: silt loam, well drained, pH about 7.0 (neutral).

Did spring come early in Santa Rosa, CA in 2026?

Spring leaf-out near 95406 came on Jan 29 in 2026, about the same as the 1991–2020 average (Jan 30), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Santa Rosa, CA?

Intermediate onions: the longest day near 95406 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 95406 change?

Yes. The 2012 USDA map put 95406 in zone 9b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.