Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 95637 — Guinda, CA

ZIP code 95637 (Guinda, Yolo County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is April 10 and the first fall frost November 6.

Where ZIP 95637 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 frostApr 10

First frostNov 6

2012 zone9a

Was 9a 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 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Guinda, 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 Guinda, CA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 10median — 50% chance of a later frost

Safe for tender plantsApril 30only 10% chance of frost after

First fall frostNovember 6median — 10% chance by Oct 24

Growing season209 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 14 and returns around November 21.

From the NOAA station Clearlake 4 Se, CA — 17 miles away, elevation 1,348 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 95637

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 27 – Mar 13

SpinachSow outdoors · Feb 27 – Mar 20

Broccoli, cabbageStart indoors · Jan 30 – Feb 13

Broccoli, cabbageTransplant · Mar 20 – Apr 3

Onion setsPlant outdoors · Mar 13 – Mar 27

PotatoesPlant outdoors · Mar 20 – Apr 3

LettuceSow outdoors · Mar 13 – Mar 27

Carrots, beetsSow outdoors · Mar 20 – Apr 3

TomatoesStart indoors · Feb 13 – Feb 27

TomatoesTransplant · Apr 17 – May 1

Peppers, eggplantStart indoors · Jan 30 – Feb 13

Peppers, eggplantTransplant · Apr 24 – May 8

BeansSow outdoors · Apr 17 – May 1

Sweet cornSow outdoors · Apr 17 – May 1

Cucumbers, squashSow outdoors · Apr 17 – May 1

Fall lettuce, spinachSow outdoors · Sep 11 – Sep 25

GarlicPlant cloves · Oct 23 – Nov 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 10) and first fall frost (Nov 6) 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 95637 came on Jan 20 — 14 days earlier than the 1991–2020 average (Feb 3).

average
Feb 32026
Jan 20

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 Guinda, CA

The soil mapped at the center of ZIP 95637 is Lithic Xerorthents, excessively drained.

DrainageExcessively drainednatural drainage class

Farmland classNot prime farmlandUSDA classification

Map unit: Rock land.

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 95637; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Guinda, CA

Summer high91 °Faverage high, July

Winter low33 °Faverage low, January

Hot days66days a year at 90 °F or more

Freezing nights72nights a year at 32 °F or less

Growing degree days3,335base 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

Precipitation29.9 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Clearlake 4 Se, CA (17 mi away); precipitation: Clearlake 4 Se, CA (17 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.

Pope Valley, CA · 15 mi

959129b

Arbuckle, CA · 15 mi

954679a

Hidden Valley Lake, CA · 15 mi

954579a

Lower Lake, CA · 16 mi

956279b

Esparto, CA · 16 mi

California planting zones →

Questions about 95637

What planting zone is ZIP code 95637?

ZIP code 95637 (Guinda, 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 Guinda, CA?

The median last spring frost (32 °F) near 95637 is April 10; after April 30 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Clearlake 4 Se station.

When is the first frost in Guinda, CA?

The median first fall frost near 95637 is November 6, giving a median frost-free growing season of 209 days.

When should I plant tomatoes in 95637?

Start tomato seeds indoors around Feb 13 – Feb 27 and set transplants outside around Apr 17 – May 1, one to three weeks after the median last frost.

How much rain and snow does 95637 get?

About 29.9 inches of precipitation a year (NOAA 1991–2020 normals, Clearlake 4 Se station).

How hot do summers get in Guinda, CA?

The average high peaks at 91 °F in July, with about 66 days a year at 90 °F or more.

Did spring come early in Guinda, CA in 2026?

Spring leaf-out near 95637 came on Jan 20 in 2026, 14 days earlier than the 1991–2020 average (Feb 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Guinda, CA?

Intermediate onions: the longest day near 95637 is 14 h 54 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 95637 change?

Yes. The 2012 USDA map put 95637 in zone 9a; the 2023 map puts it in zone 9b. The newer map uses 1991–2020 data and more weather stations.