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

Planting zone for 95559 — Phillipsville, CA

ZIP code 95559 (Phillipsville, Humboldt County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 10 and the first fall frost December 1.

Where ZIP 95559 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostMar 10
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 Phillipsville, 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 Phillipsville, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 10median — 50% chance of a later frost
Safe for tender plantsApril 13only 10% chance of frost after
First fall frostDecember 1median — 10% chance by Nov 7
Growing season271 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 15 and returns around December 26.

From the NOAA station Richardson Gr Sp, CA — 12 miles away, elevation 502 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 95559

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 27 – Feb 10
SpinachSow outdoors · Jan 27 – Feb 17
Broccoli, cabbageStart indoors · Dec 30 – Jan 13
Broccoli, cabbageTransplant · Feb 17 – Mar 3
Onion setsPlant outdoors · Feb 10 – Feb 24
PotatoesPlant outdoors · Feb 17 – Mar 3
LettuceSow outdoors · Feb 10 – Feb 24
Carrots, beetsSow outdoors · Feb 17 – Mar 3
TomatoesStart indoors · Jan 13 – Jan 27
TomatoesTransplant · Mar 17 – Mar 31
Peppers, eggplantStart indoors · Dec 30 – Jan 13
Peppers, eggplantTransplant · Mar 24 – Apr 7
BeansSow outdoors · Mar 17 – Mar 31
Sweet cornSow outdoors · Mar 17 – Mar 31
Cucumbers, squashSow outdoors · Mar 17 – Mar 31
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 (Mar 10) 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 95559 came on Jan 28 — 10 days earlier than the 1991–2020 average (Feb 7).

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 Phillipsville, CA

The soil mapped at the center of ZIP 95559 is Coolyork — loam, moderately well drained.

TextureLoama good balance for most vegetables
pH5.6moderately acidic; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter4%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Coolyork-Yorknorth complex, 30 to 50 percent slopes.

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 95559; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Phillipsville, CA

Summer high87 °Faverage high, August
Winter low38 °Faverage low, December
Hot days30days a year at 90 °F or more
Freezing nights22nights a year at 32 °F or less
Growing degree days2,942base 50 °F — the season’s usable heat
Longest day15 h 02 mindaylight on June 21
Shortest day9 h 18 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation66.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 50 °F, low 39 °F 50°39° JanFebruary: average high 53 °F, low 40 °F 53°40° FebMarch: average high 59 °F, low 41 °F 59°41° MarApril: average high 64 °F, low 42 °F 64°42° AprMay: average high 72 °F, low 47 °F 72°47° MayJune: average high 77 °F, low 51 °F 77°51° JunJuly: average high 86 °F, low 54 °F 86°54° JulAugust: average high 87 °F, low 54 °F 87°54° AugSeptember: average high 83 °F, low 50 °F 83°50° SepOctober: average high 70 °F, low 45 °F 70°45° OctNovember: average high 55 °F, low 41 °F 55°41° NovDecember: average high 49 °F, low 38 °F 49°38° Dec

Precipitation by month inches

0″2″4″6″8″10″12″14″January: 11.78 in precipitation 11.8 JanFebruary: 10.37 in precipitation 10.4 FebMarch: 9.47 in precipitation 9.5 MarApril: 4.94 in precipitation 4.9 AprMay: 2.61 in precipitation 2.6 MayJune: 0.87 in precipitation 0.9 JunJuly: 0.14 in precipitation 0.1 JulAugust: 0.12 in precipitation 0.1 AugSeptember: 0.61 in precipitation 0.6 SepOctober: 3.72 in precipitation 3.7 OctNovember: 7.75 in precipitation 7.8 NovDecember: 13.94 in precipitation 13.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Richardson Gr Sp, CA (12 mi away); precipitation: Miranda 4.1 Sw, CA (8 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.

955609b
Redway, CA · 6 mi
955429a
Garberville, CA · 7 mi
955539b
Miranda, CA · 7 mi
955549b
Myers Flat, CA · 7 mi
955149a
Blocksburg, CA · 8 mi
955119a
Alderpoint, CA · 9 mi
955699b
Redcrest, CA · 13 mi
955899b
Whitethorn, CA · 15 mi

California planting zones →

Questions about 95559

What planting zone is ZIP code 95559?

ZIP code 95559 (Phillipsville, 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 Phillipsville, CA?

The median last spring frost (32 °F) near 95559 is March 10; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Richardson Gr Sp station.

When is the first frost in Phillipsville, CA?

The median first fall frost near 95559 is December 1, giving a median frost-free growing season of 271 days.

When should I plant tomatoes in 95559?

Start tomato seeds indoors around Jan 13 – Jan 27 and set transplants outside around Mar 17 – Mar 31, one to three weeks after the median last frost.

How much rain and snow does 95559 get?

About 66.3 inches of precipitation a year (NOAA 1991–2020 normals, Miranda 4.1 Sw station).

How hot do summers get in Phillipsville, CA?

The average high peaks at 87 °F in August, with about 30 days a year at 90 °F or more.

What kind of soil does 95559 have?

The USDA soil survey maps Coolyork at the center of ZIP 95559: loam, moderately well drained, pH about 5.6 (moderately acidic).

Did spring come early in Phillipsville, CA in 2026?

Spring leaf-out near 95559 came on Jan 28 in 2026, 10 days earlier than the 1991–2020 average (Feb 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Phillipsville, CA?

Long-day onions: the longest day near 95559 is 15 h 02 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 95559 change?

Yes. The 2012 USDA map put 95559 in zone 9b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.