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

Planting zone for 95663 — Penryn, CA

ZIP code 95663 (Penryn, Placer County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 25 and the first fall frost December 5.

Where ZIP 95663 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 25
First frostDec 5
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 Penryn, 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 Penryn, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 25median — 50% chance of a later frost
Safe for tender plantsApril 7only 10% chance of frost after
First fall frostDecember 5median — 10% chance by Nov 15
Growing season286 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 13 and returns around December 22.

From the NOAA station Auburn, CA — 6 miles away, elevation 1,293 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 95663

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 14 – Jan 28
SpinachSow outdoors · Jan 14 – Feb 4
Broccoli, cabbageStart indoors · Dec 17 – Dec 31
Broccoli, cabbageTransplant · Feb 4 – Feb 18
Onion setsPlant outdoors · Jan 28 – Feb 11
PotatoesPlant outdoors · Feb 4 – Feb 18
LettuceSow outdoors · Jan 28 – Feb 11
Carrots, beetsSow outdoors · Feb 4 – Feb 18
TomatoesStart indoors · Dec 31 – Jan 14
TomatoesTransplant · Mar 4 – Mar 18
Peppers, eggplantStart indoors · Dec 17 – Dec 31
Peppers, eggplantTransplant · Mar 11 – Mar 25
BeansSow outdoors · Mar 4 – Mar 18
Sweet cornSow outdoors · Mar 4 – Mar 18
Cucumbers, squashSow outdoors · Mar 4 – Mar 18
Fall lettuce, spinachSow outdoors · Oct 10 – Oct 24
GarlicPlant cloves · Nov 21 – Dec 26
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 25) and first fall frost (Dec 5) 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 95663 came on Jan 30 — 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 Penryn, CA

The soil mapped at the center of ZIP 95663 is Andregg — coarse sandy loam, well drained.

TextureCoarse sandy loamdrains and warms fast; dries out and needs more feeding
pH6.5neutral; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupBwater soaks in moderately
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Andregg coarse sandy loam, 2 to 9 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 95663; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Penryn, CA

Summer high93 °Faverage high, July
Winter low37 °Faverage low, December
Hot days63days a year at 90 °F or more
Freezing nights20nights a year at 32 °F or less
Growing degree days4,541base 50 °F — the season’s usable heat
Longest day14 h 54 mindaylight on June 21
Shortest day9 h 26 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation30.7 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°90°100°32 °FJanuary: average high 56 °F, low 38 °F 56°38° JanFebruary: average high 59 °F, low 40 °F 59°40° FebMarch: average high 63 °F, low 42 °F 63°42° MarApril: average high 68 °F, low 45 °F 68°45° AprMay: average high 77 °F, low 52 °F 77°52° MayJune: average high 86 °F, low 58 °F 86°58° JunJuly: average high 93 °F, low 63 °F 93°63° JulAugust: average high 92 °F, low 63 °F 92°63° AugSeptember: average high 87 °F, low 60 °F 87°60° SepOctober: average high 77 °F, low 52 °F 77°52° OctNovember: average high 64 °F, low 43 °F 64°43° NovDecember: average high 56 °F, low 37 °F 56°37° Dec

Precipitation by month inches

0″1″2″3″4″5″6″January: 5.35 in precipitation 5.3 JanFebruary: 5.42 in precipitation 5.4 FebMarch: 4.67 in precipitation 4.7 MarApril: 2.67 in precipitation 2.7 AprMay: 1.23 in precipitation 1.2 MayJune: 0.50 in precipitation 0.5 JunJuly: 0.01 in precipitation 0.0 JulAugust: 0.06 in precipitation 0.1 AugSeptember: 0.28 in precipitation 0.3 SepOctober: 1.48 in precipitation 1.5 OctNovember: 3.12 in precipitation 3.1 NovDecember: 5.93 in precipitation 5.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Auburn, CA (6 mi away); precipitation: Penryn 0.4 Se, CA (within 1 mile). 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.

956589b
Newcastle, CA · 2 mi
956509b
Loomis, CA · 3 mi
956779b
Rocklin, CA · 5 mi
957659b
Rocklin, CA · 6 mi
956039b
Auburn, CA · 6 mi
957469b
Granite Bay, CA · 8 mi
956489a
Lincoln, CA · 8 mi
956789b
Roseville, CA · 9 mi

California planting zones →

Questions about 95663

What planting zone is ZIP code 95663?

ZIP code 95663 (Penryn, 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 Penryn, CA?

The median last spring frost (32 °F) near 95663 is February 25; after April 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Auburn station.

When is the first frost in Penryn, CA?

The median first fall frost near 95663 is December 5, giving a median frost-free growing season of 286 days.

When should I plant tomatoes in 95663?

Start tomato seeds indoors around Dec 31 – Jan 14 and set transplants outside around Mar 4 – Mar 18, one to three weeks after the median last frost.

How much rain and snow does 95663 get?

About 30.7 inches of precipitation a year (NOAA 1991–2020 normals, Penryn 0.4 Se station).

How hot do summers get in Penryn, CA?

The average high peaks at 93 °F in July, with about 63 days a year at 90 °F or more.

What kind of soil does 95663 have?

The USDA soil survey maps Andregg at the center of ZIP 95663: coarse sandy loam, well drained, pH about 6.5 (neutral).

Did spring come early in Penryn, CA in 2026?

Spring leaf-out near 95663 came on Jan 30 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 Penryn, CA?

Intermediate onions: the longest day near 95663 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.