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

Planting zone for 95310 — Columbia, CA

ZIP code 95310 (Columbia, Tuolumne County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 20 and the first fall frost December 11.

Where ZIP 95310 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 frostFeb 20
First frostDec 11
2012 zone9a

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 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Columbia, 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 Columbia, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 20median — 50% chance of a later frost
Safe for tender plantsApril 7only 10% chance of frost after
First fall frostDecember 11median — 10% chance by Nov 24
Growing season290 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 6 and returns around December 24.

From the NOAA station New Melones Dam Hq, CA — 8 miles away, elevation 961 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 95310

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 9 – Jan 23
SpinachSow outdoors · Jan 9 – Jan 30
Broccoli, cabbageStart indoors · Dec 12 – Dec 26
Broccoli, cabbageTransplant · Jan 30 – Feb 13
Onion setsPlant outdoors · Jan 23 – Feb 6
PotatoesPlant outdoors · Jan 30 – Feb 13
LettuceSow outdoors · Jan 23 – Feb 6
Carrots, beetsSow outdoors · Jan 30 – Feb 13
TomatoesStart indoors · Dec 26 – Jan 9
TomatoesTransplant · Feb 27 – Mar 13
Peppers, eggplantStart indoors · Dec 12 – Dec 26
Peppers, eggplantTransplant · Mar 6 – Mar 20
BeansSow outdoors · Feb 27 – Mar 13
Sweet cornSow outdoors · Feb 27 – Mar 13
Cucumbers, squashSow outdoors · Feb 27 – Mar 13
Fall lettuce, spinachSow outdoors · Oct 16 – Oct 30
GarlicPlant cloves · Nov 27 – Jan 1
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 20) and first fall frost (Dec 11) 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 95310 came on Jan 24 — 14 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 Columbia, CA

The soil mapped at the center of ZIP 95310 is Pinole family — gravelly loam, well drained.

TextureGravelly loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupCwater soaks in slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Pinole-Holland, deep families association, 5 to 35 perc ent slope s.

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 95310; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Columbia, CA

Summer high97 °Faverage high, July
Winter low38 °Faverage low, January
Hot days98days a year at 90 °F or more
Freezing nights13nights a year at 32 °F or less
Growing degree days5,108base 50 °F — the season’s usable heat
Longest day14 h 49 mindaylight on June 21
Shortest day9 h 31 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation29.8 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°110°32 °FJanuary: average high 57 °F, low 38 °F 57°38° JanFebruary: average high 61 °F, low 40 °F 61°40° FebMarch: average high 65 °F, low 44 °F 65°44° MarApril: average high 70 °F, low 46 °F 70°46° AprMay: average high 79 °F, low 52 °F 79°52° MayJune: average high 89 °F, low 59 °F 89°59° JunJuly: average high 97 °F, low 65 °F 97°65° JulAugust: average high 96 °F, low 65 °F 96°65° AugSeptember: average high 91 °F, low 60 °F 91°60° SepOctober: average high 80 °F, low 52 °F 80°52° OctNovember: average high 66 °F, low 44 °F 66°44° NovDecember: average high 57 °F, low 38 °F 57°38° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.85 in precipitation 5.8 JanFebruary: 4.85 in precipitation 4.8 FebMarch: 4.77 in precipitation, 0.2 in snowfall 4.8 MarApril: 2.58 in precipitation 2.6 AprMay: 1.48 in precipitation 1.5 MayJune: 0.36 in precipitation 0.4 JunJuly: 0.03 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.21 in precipitation 0.2 SepOctober: 1.51 in precipitation 1.5 OctNovember: 2.91 in precipitation 2.9 NovDecember: 5.16 in precipitation 5.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: New Melones Dam Hq, CA (8 mi away); precipitation: New Melones Dam Hq, CA (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

952519a
Vallecito, CA · 4 mi
952299a
Douglas Flat, CA · 5 mi
952479a
Murphys, CA · 5 mi
952338b
Hathaway Pines, CA · 7 mi
953709a
Sonora, CA · 7 mi
953838b
Twain Harte, CA · 8 mi
953739a
Standard, CA · 9 mi
953728b
Soulsbyville, CA · 9 mi

California planting zones →

Questions about 95310

What planting zone is ZIP code 95310?

ZIP code 95310 (Columbia, 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 Columbia, CA?

The median last spring frost (32 °F) near 95310 is February 20; after April 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, New Melones Dam Hq station.

When is the first frost in Columbia, CA?

The median first fall frost near 95310 is December 11, giving a median frost-free growing season of 290 days.

When should I plant tomatoes in 95310?

Start tomato seeds indoors around Dec 26 – Jan 9 and set transplants outside around Feb 27 – Mar 13, one to three weeks after the median last frost.

How much rain and snow does 95310 get?

About 29.8 inches of precipitation a year (NOAA 1991–2020 normals, New Melones Dam Hq station).

How hot do summers get in Columbia, CA?

The average high peaks at 97 °F in July, with about 98 days a year at 90 °F or more.

What kind of soil does 95310 have?

The USDA soil survey maps Pinole family at the center of ZIP 95310: gravelly loam, well drained, pH about 6.7 (neutral).

Did spring come early in Columbia, CA in 2026?

Spring leaf-out near 95310 came on Jan 24 in 2026, 14 days earlier than the 1991–2020 average (Feb 7), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Columbia, CA?

Intermediate onions: the longest day near 95310 is 14 h 49 min, so day-neutral types bulb best; long-day varieties may not bulb fully.