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

Planting zone for 95428 — Covelo, CA

ZIP code 95428 (Covelo, Mendocino County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is April 23 and the first fall frost October 19.

Where ZIP 95428 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 frostApr 23
First frostOct 19
2012 zone8b

Was 8b 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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Covelo, 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 Covelo, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 23median — 50% chance of a later frost
Safe for tender plantsMay 11only 10% chance of frost after
First fall frostOctober 19median — 10% chance by Oct 2
Growing season179 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 29 and returns around November 3.

From the NOAA station Covelo, CA — 4 miles away, elevation 1,414 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 95428

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 12 – Mar 26
SpinachSow outdoors · Mar 12 – Apr 2
Broccoli, cabbageStart indoors · Feb 12 – Feb 26
Broccoli, cabbageTransplant · Apr 2 – Apr 16
Onion setsPlant outdoors · Mar 26 – Apr 9
PotatoesPlant outdoors · Apr 2 – Apr 16
LettuceSow outdoors · Mar 26 – Apr 9
Carrots, beetsSow outdoors · Apr 2 – Apr 16
TomatoesStart indoors · Feb 26 – Mar 12
TomatoesTransplant · Apr 30 – May 14
Peppers, eggplantStart indoors · Feb 12 – Feb 26
Peppers, eggplantTransplant · May 7 – May 21
BeansSow outdoors · Apr 30 – May 14
Sweet cornSow outdoors · Apr 30 – May 14
Cucumbers, squashSow outdoors · Apr 30 – May 14
Fall lettuce, spinachSow outdoors · Aug 24 – Sep 7
GarlicPlant cloves · Oct 5 – Nov 9
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 23) and first fall frost (Oct 19) 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 95428 came on Feb 1 — 8 days earlier than the 1991–2020 average (Feb 9).

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 Covelo, CA

The soil mapped at the center of ZIP 95428 is Shortyork — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter3.5%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Shortyork-Yorkville-Witherell complex, 30 to 50 percent slopes, MLRA 5.

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 95428; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Covelo, CA

Summer high92 °Faverage high, July
Winter low32 °Faverage low, December
Hot days74days a year at 90 °F or more
Freezing nights77nights a year at 32 °F or less
Growing degree days3,078base 50 °F — the season’s usable heat
Longest day15 h 00 mindaylight on June 21
Shortest day9 h 21 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation40.4 inper year, rain and melted snow
Snowfall3 inper year

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 52 °F, low 33 °F 52°33° JanFebruary: average high 57 °F, low 34 °F 57°34° FebMarch: average high 62 °F, low 36 °F 62°36° MarApril: average high 67 °F, low 38 °F 67°38° AprMay: average high 75 °F, low 43 °F 75°43° MayJune: average high 84 °F, low 48 °F 84°48° JunJuly: average high 92 °F, low 53 °F 92°53° JulAugust: average high 91 °F, low 51 °F 91°51° AugSeptember: average high 88 °F, low 45 °F 88°45° SepOctober: average high 76 °F, low 39 °F 76°39° OctNovember: average high 58 °F, low 35 °F 58°35° NovDecember: average high 50 °F, low 32 °F 50°32° Dec

Precipitation by month inches · ❄ = snowfall

0″2″4″6″8″January: 7.82 in precipitation, 0.7 in snowfall 7.8❄1 JanFebruary: 6.76 in precipitation, 1.4 in snowfall 6.8❄1 FebMarch: 5.19 in precipitation, 0.2 in snowfall 5.2 MarApril: 2.81 in precipitation, 0.2 in snowfall 2.8 AprMay: 1.64 in precipitation 1.6 MayJune: 0.76 in precipitation 0.8 JunJuly: 0.03 in precipitation 0.0 JulAugust: 0.16 in precipitation 0.2 AugSeptember: 0.20 in precipitation 0.2 SepOctober: 2.00 in precipitation 2.0 OctNovember: 4.28 in precipitation, 0.2 in snowfall 4.3 NovDecember: 8.79 in precipitation, 0.6 in snowfall 8.8❄1 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Covelo, CA (4 mi away); precipitation: Covelo, CA (4 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.

954299a
Dos Rios, CA · 11 mi
954549a
Laytonville, CA · 17 mi
955958b
Zenia, CA · 18 mi
954909a
Willits, CA · 26 mi
955859a
Leggett, CA · 26 mi
954179a
Branscomb, CA · 27 mi
954699a
Potter Valley, CA · 30 mi
960749b
Paskenta, CA · 31 mi

California planting zones →

Questions about 95428

What planting zone is ZIP code 95428?

ZIP code 95428 (Covelo, 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 Covelo, CA?

The median last spring frost (32 °F) near 95428 is April 23; after May 11 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Covelo station.

When is the first frost in Covelo, CA?

The median first fall frost near 95428 is October 19, giving a median frost-free growing season of 179 days.

When should I plant tomatoes in 95428?

Start tomato seeds indoors around Feb 26 – Mar 12 and set transplants outside around Apr 30 – May 14, one to three weeks after the median last frost.

How much rain and snow does 95428 get?

About 40.4 inches of precipitation a year and 3 inches of snowfall (NOAA 1991–2020 normals, Covelo station).

How hot do summers get in Covelo, CA?

The average high peaks at 92 °F in July, with about 74 days a year at 90 °F or more.

What kind of soil does 95428 have?

The USDA soil survey maps Shortyork at the center of ZIP 95428: gravelly loam, well drained, pH about 6.5 (neutral).

Did spring come early in Covelo, CA in 2026?

Spring leaf-out near 95428 came on Feb 1 in 2026, 8 days earlier than the 1991–2020 average (Feb 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Covelo, CA?

Intermediate onions: the longest day near 95428 is 15 h 00 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 95428 change?

Yes. The 2012 USDA map put 95428 in zone 8b; the 2023 map puts it in zone 9a. The newer map uses 1991–2020 data and more weather stations.