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

Planting zone for 95974 — Richvale, CA

ZIP code 95974 (Richvale, Butte County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 29 and the first fall frost December 7.

Where ZIP 95974 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 frostJan 29
First frostDec 7
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 Richvale, 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 Richvale, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostJanuary 29median — 50% chance of a later frost
Safe for tender plantsFebruary 28only 10% chance of frost after
First fall frostDecember 7median — 10% chance by Nov 20
Growing season317 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 9 and returns around December 27.

From the NOAA station Oroville Municipal Airport, CA — 7 miles away, elevation 190 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 95974

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Dec 18 – Jan 1
SpinachSow outdoors · Dec 18 – Jan 8
Broccoli, cabbageStart indoors · Nov 20 – Dec 4
Broccoli, cabbageTransplant · Jan 8 – Jan 22
Onion setsPlant outdoors · Jan 1 – Jan 15
PotatoesPlant outdoors · Jan 8 – Jan 22
LettuceSow outdoors · Jan 1 – Jan 15
Carrots, beetsSow outdoors · Jan 8 – Jan 22
TomatoesStart indoors · Dec 4 – Dec 18
TomatoesTransplant · Feb 5 – Feb 19
Peppers, eggplantStart indoors · Nov 20 – Dec 4
Peppers, eggplantTransplant · Feb 12 – Feb 26
BeansSow outdoors · Feb 5 – Feb 19
Sweet cornSow outdoors · Feb 5 – Feb 19
Cucumbers, squashSow outdoors · Feb 5 – Feb 19
Fall lettuce, spinachSow outdoors · Oct 12 – Oct 26
GarlicPlant cloves · Nov 23 – Dec 28
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Jan 29) and first fall frost (Dec 7) 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 95974 came on Jan 31 — about the same time as the 1991–2020 average (Feb 1).

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 Richvale, CA

The soil mapped at the center of ZIP 95974 is Esquon — clay, poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH4.5strongly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter2.3%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classPrime farmland if irrigatedUSDA classification

Map unit: Esquon-Neerdobe , 0 to 1 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 95974; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Richvale, CA

Summer high96 °Faverage high, July
Winter low40 °Faverage low, January
Hot days93days a year at 90 °F or more
Freezing nights11nights a year at 32 °F or less
Growing degree days5,120base 50 °F — the season’s usable heat
Longest day14 h 58 mindaylight on June 21
Shortest day9 h 23 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation25.7 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 55 °F, low 40 °F 55°40° JanFebruary: average high 61 °F, low 42 °F 61°42° FebMarch: average high 66 °F, low 45 °F 66°45° MarApril: average high 72 °F, low 49 °F 72°49° AprMay: average high 81 °F, low 55 °F 81°55° MayJune: average high 90 °F, low 61 °F 90°61° JunJuly: average high 96 °F, low 65 °F 96°65° JulAugust: average high 94 °F, low 64 °F 94°64° AugSeptember: average high 89 °F, low 59 °F 89°59° SepOctober: average high 78 °F, low 52 °F 78°52° OctNovember: average high 64 °F, low 44 °F 64°44° NovDecember: average high 55 °F, low 40 °F 55°40° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.20 in precipitation 5.2 JanFebruary: 4.79 in precipitation 4.8 FebMarch: 3.33 in precipitation 3.3 MarApril: 1.80 in precipitation 1.8 AprMay: 1.05 in precipitation 1.1 MayJune: 0.32 in precipitation 0.3 JunJuly: 0.04 in precipitation 0.0 JulAugust: 0.04 in precipitation 0.0 AugSeptember: 0.16 in precipitation 0.2 SepOctober: 1.44 in precipitation 1.4 OctNovember: 2.87 in precipitation 2.9 NovDecember: 4.63 in precipitation 4.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Oroville Municipal Airport, CA (7 mi away); precipitation: Oroville Municipal Airport, CA (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

959179b
Biggs, CA · 4 mi
959589b
Nelson, CA · 5 mi
959389a
Durham, CA · 8 mi
959209b
Butte City, CA · 10 mi
959489b
Gridley, CA · 11 mi
959659b
Oroville, CA · 11 mi
959689b
Palermo, CA · 12 mi
959289b
Chico, CA · 13 mi

California planting zones →

Questions about 95974

What planting zone is ZIP code 95974?

ZIP code 95974 (Richvale, 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 Richvale, CA?

The median last spring frost (32 °F) near 95974 is January 29; after February 28 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Oroville Municipal Airport station.

When is the first frost in Richvale, CA?

The median first fall frost near 95974 is December 7, giving a median frost-free growing season of 317 days.

When should I plant tomatoes in 95974?

Start tomato seeds indoors around Dec 4 – Dec 18 and set transplants outside around Feb 5 – Feb 19, one to three weeks after the median last frost.

How much rain and snow does 95974 get?

About 25.7 inches of precipitation a year (NOAA 1991–2020 normals, Oroville Municipal Airport station).

How hot do summers get in Richvale, CA?

The average high peaks at 96 °F in July, with about 93 days a year at 90 °F or more.

What kind of soil does 95974 have?

The USDA soil survey maps Esquon at the center of ZIP 95974: clay, poorly drained, pH about 4.5 (strongly acidic).

Did spring come early in Richvale, CA in 2026?

Spring leaf-out near 95974 came on Jan 31 in 2026, about the same as the 1991–2020 average (Feb 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Richvale, CA?

Intermediate onions: the longest day near 95974 is 14 h 58 min, so day-neutral types bulb best; long-day varieties may not bulb fully.