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

Planting zone for 95409 — Santa Rosa, CA

ZIP code 95409 (Santa Rosa, Sonoma County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 3 and the first fall frost December 4.

Where ZIP 95409 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 frostFeb 3
First frostDec 4
2012 zone9b

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 9b 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 3median — 50% chance of a later frost
Safe for tender plantsMarch 13only 10% chance of frost after
First fall frostDecember 4median — 10% chance by Nov 14
Growing season306 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 5 and returns around December 17.

From the NOAA station Saint Helena, CA — 7 miles away, elevation 226 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 95409

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 23 – Jan 6
SpinachSow outdoors · Dec 23 – Jan 13
Broccoli, cabbageStart indoors · Nov 25 – Dec 9
Broccoli, cabbageTransplant · Jan 13 – Jan 27
Onion setsPlant outdoors · Jan 6 – Jan 20
PotatoesPlant outdoors · Jan 13 – Jan 27
LettuceSow outdoors · Jan 6 – Jan 20
Carrots, beetsSow outdoors · Jan 13 – Jan 27
TomatoesStart indoors · Dec 9 – Dec 23
TomatoesTransplant · Feb 10 – Feb 24
Peppers, eggplantStart indoors · Nov 25 – Dec 9
Peppers, eggplantTransplant · Feb 17 – Mar 3
BeansSow outdoors · Feb 10 – Feb 24
Sweet cornSow outdoors · Feb 10 – Feb 24
Cucumbers, squashSow outdoors · Feb 10 – Feb 24
Fall lettuce, spinachSow outdoors · Oct 9 – Oct 23
GarlicPlant cloves · Nov 20 – Dec 25
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 3) and first fall frost (Dec 4) 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 95409 came on Jan 23 — 7 days earlier than 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 center of ZIP 95409 is mapped as Rock land: built-over ground without natural soil data. Garden soil here is usually imported or disturbed — test before you plant.

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 95409; 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 high89 °Faverage high, July
Winter low40 °Faverage low, January
Hot days55days a year at 90 °F or more
Freezing nights14nights a year at 32 °F or less
Growing degree days4,262base 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
Precipitation35.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 59 °F, low 40 °F 59°40° JanFebruary: average high 63 °F, low 42 °F 63°42° FebMarch: average high 67 °F, low 44 °F 67°44° MarApril: average high 72 °F, low 46 °F 72°46° AprMay: average high 78 °F, low 51 °F 78°51° MayJune: average high 85 °F, low 54 °F 85°54° JunJuly: average high 89 °F, low 56 °F 89°56° JulAugust: average high 89 °F, low 56 °F 89°56° AugSeptember: average high 87 °F, low 54 °F 87°54° SepOctober: average high 78 °F, low 49 °F 78°49° OctNovember: average high 66 °F, low 44 °F 66°44° NovDecember: average high 58 °F, low 40 °F 58°40° Dec

Precipitation by month inches

0″2″4″6″8″January: 7.03 in precipitation 7.0 JanFebruary: 6.95 in precipitation 7.0 FebMarch: 4.84 in precipitation 4.8 MarApril: 2.39 in precipitation 2.4 AprMay: 1.45 in precipitation 1.4 MayJune: 0.36 in precipitation 0.4 JunJuly: 0.01 in precipitation 0.0 JulAugust: 0.05 in precipitation 0.1 AugSeptember: 0.16 in precipitation 0.2 SepOctober: 1.78 in precipitation 1.8 OctNovember: 3.54 in precipitation 3.5 NovDecember: 6.78 in precipitation 6.8 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Saint Helena, CA (7 mi away); precipitation: Santa Rosa 1.7 E, CA (5 mi away). 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.

954529b
Kenwood, CA · 4 mi
954059a
Santa Rosa, CA · 5 mi
954049b
Santa Rosa, CA · 7 mi
954029b
Santa Rosa, CA · 7 mi
954069a
Santa Rosa, CA · 7 mi
954429b
Glen Ellen, CA · 7 mi
945769b
Deer Park, CA · 8 mi
945739b
Rutherford, CA · 8 mi

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

Questions about 95409

What planting zone is ZIP code 95409?

ZIP code 95409 (Santa Rosa, 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 Santa Rosa, CA?

The median last spring frost (32 °F) near 95409 is February 3; after March 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Saint Helena station.

When is the first frost in Santa Rosa, CA?

The median first fall frost near 95409 is December 4, giving a median frost-free growing season of 306 days.

When should I plant tomatoes in 95409?

Start tomato seeds indoors around Dec 9 – Dec 23 and set transplants outside around Feb 10 – Feb 24, one to three weeks after the median last frost.

How much rain and snow does 95409 get?

About 35.3 inches of precipitation a year (NOAA 1991–2020 normals, Santa Rosa 1.7 E station).

How hot do summers get in Santa Rosa, CA?

The average high peaks at 89 °F in July, with about 55 days a year at 90 °F or more.

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

Spring leaf-out near 95409 came on Jan 23 in 2026, 7 days earlier than 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 95409 is 14 h 51 min, so day-neutral types bulb best; long-day varieties may not bulb fully.