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

Planting zone for 93661 — Santa Rita Park, CA

ZIP code 93661 (Santa Rita Park, Merced County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is February 26 and the first fall frost November 25.

Where ZIP 93661 is

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 26
First frostNov 25
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 Santa Rita Park, 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 Santa Rita Park, CA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostFebruary 26median — 50% chance of a later frost
Safe for tender plantsApril 1only 10% chance of frost after
First fall frostNovember 25median — 10% chance by Nov 9
Growing season273 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 22 and returns around December 10.

From the NOAA station Merced Municipal Airport, CA — 10 miles away, elevation 151 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 93661

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Jan 15 – Jan 29
SpinachSow outdoors · Jan 15 – Feb 5
Broccoli, cabbageStart indoors · Dec 18 – Jan 1
Broccoli, cabbageTransplant · Feb 5 – Feb 19
Onion setsPlant outdoors · Jan 29 – Feb 12
PotatoesPlant outdoors · Feb 5 – Feb 19
LettuceSow outdoors · Jan 29 – Feb 12
Carrots, beetsSow outdoors · Feb 5 – Feb 19
TomatoesStart indoors · Jan 1 – Jan 15
TomatoesTransplant · Mar 5 – Mar 19
Peppers, eggplantStart indoors · Dec 18 – Jan 1
Peppers, eggplantTransplant · Mar 12 – Mar 26
BeansSow outdoors · Mar 5 – Mar 19
Sweet cornSow outdoors · Mar 5 – Mar 19
Cucumbers, squashSow outdoors · Mar 5 – Mar 19
Fall lettuce, spinachSow outdoors · Sep 30 – Oct 14
GarlicPlant cloves · Nov 11 – Dec 16
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 26) and first fall frost (Nov 25) 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 93661 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 Santa Rita Park, CA

The soil mapped at the center of ZIP 93661 is Rossi — clay, poorly drained.

TextureClayholds water and nutrients; slow to drain and warm up
pH7.3neutral; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter2.5%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Rossi clay, moderately saline-alkali, 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 93661; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Santa Rita Park, CA

Summer high96 °Faverage high, July
Winter low36 °Faverage low, December
Hot days100days a year at 90 °F or more
Freezing nights28nights a year at 32 °F or less
Growing degree days4,882base 50 °F — the season’s usable heat
Longest day14 h 43 mindaylight on June 21
Shortest day9 h 36 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation11.8 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 56 °F, low 37 °F 56°37° JanFebruary: average high 62 °F, low 39 °F 62°39° FebMarch: average high 68 °F, low 42 °F 68°42° MarApril: average high 74 °F, low 45 °F 74°45° AprMay: average high 83 °F, low 52 °F 83°52° MayJune: average high 91 °F, low 58 °F 91°58° JunJuly: average high 96 °F, low 62 °F 96°62° JulAugust: average high 95 °F, low 61 °F 95°61° AugSeptember: average high 91 °F, low 57 °F 91°57° SepOctober: average high 80 °F, low 49 °F 80°49° OctNovember: average high 66 °F, low 41 °F 66°41° NovDecember: average high 56 °F, low 36 °F 56°36° Dec

Precipitation by month inches

0″1″2″3″January: 2.37 in precipitation 2.4 JanFebruary: 2.20 in precipitation 2.2 FebMarch: 1.82 in precipitation 1.8 MarApril: 1.12 in precipitation 1.1 AprMay: 0.55 in precipitation 0.6 MayJune: 0.12 in precipitation 0.1 JunJuly: 0.00 in precipitation 0.0 JulAugust: 0.00 in precipitation 0.0 AugSeptember: 0.05 in precipitation 0.1 SepOctober: 0.64 in precipitation 0.6 OctNovember: 1.02 in precipitation 1.0 NovDecember: 1.91 in precipitation 1.9 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Merced Municipal Airport, CA (10 mi away); precipitation: Merced Municipal Airport, CA (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9a.

953019a
Atwater, CA · 8 mi
953419a
Merced, CA · 9 mi
953179a
El Nido, CA · 9 mi
936209a
Dos Palos, CA · 10 mi
953349a
Livingston, CA · 13 mi
953439a
Merced, CA · 13 mi
953449a
Merced, CA · 13 mi
953749a
Stevinson, CA · 14 mi

California planting zones →

Questions about 93661

What planting zone is ZIP code 93661?

ZIP code 93661 (Santa Rita Park, 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 Santa Rita Park, CA?

The median last spring frost (32 °F) near 93661 is February 26; after April 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Merced Municipal Airport station.

When is the first frost in Santa Rita Park, CA?

The median first fall frost near 93661 is November 25, giving a median frost-free growing season of 273 days.

When should I plant tomatoes in 93661?

Start tomato seeds indoors around Jan 1 – Jan 15 and set transplants outside around Mar 5 – Mar 19, one to three weeks after the median last frost.

How much rain and snow does 93661 get?

About 11.8 inches of precipitation a year (NOAA 1991–2020 normals, Merced Municipal Airport station).

How hot do summers get in Santa Rita Park, CA?

The average high peaks at 96 °F in July, with about 100 days a year at 90 °F or more.

What kind of soil does 93661 have?

The USDA soil survey maps Rossi at the center of ZIP 93661: clay, poorly drained, pH about 7.3 (neutral).

Did spring come early in Santa Rita Park, CA in 2026?

Spring leaf-out near 93661 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 Santa Rita Park, CA?

Intermediate onions: the longest day near 93661 is 14 h 43 min, so day-neutral types bulb best; long-day varieties may not bulb fully.