Planting zone for 92599 — Perris, CA
ZIP code 92599 (Perris, Riverside County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is January 28 and the first fall frost December 18.
Where ZIP 92599 is
tap the map for the zone at any spot · scroll or pinch to zoomNot 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.
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 ServiceLoading the forecast for Perris, 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 Perris, CA
A hard freeze (28 °F) usually ends around January 1 and returns around December 27.
From the NOAA station Elsinore, CA — 9 miles away, elevation 1,270 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 92599
Counted from the median last spring frost (Jan 28) and first fall frost (Dec 18) 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 92599 came on Jan 19 — 6 days earlier than the 1991–2020 average (Jan 25).
Jan 252026
Jan 19
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 Perris, CA
The soil mapped at the center of ZIP 92599 is Exeter — sandy loam, well drained.
Map unit: Exeter sandy loam, deep, 0 to 2 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 92599; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.
Climate in Perris, CA
Average high and low, by month
Precipitation by month inches
NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: March AFB, CA (8 mi away); precipitation: March AFB, CA (8 mi away). Daylight is calculated from latitude.
Nearby ZIP codes
All 8 nearest ZIP codes share zone 9b.
Questions about 92599
What planting zone is ZIP code 92599?
ZIP code 92599 (Perris, 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 Perris, CA?
The median last spring frost (32 °F) near 92599 is January 28; after February 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Elsinore station.
When is the first frost in Perris, CA?
The median first fall frost near 92599 is December 18, giving a median frost-free growing season of 329 days.
When should I plant tomatoes in 92599?
Start tomato seeds indoors around Dec 3 – Dec 17 and set transplants outside around Feb 4 – Feb 18, one to three weeks after the median last frost.
How much rain and snow does 92599 get?
About 10.7 inches of precipitation a year (NOAA 1991–2020 normals, March AFB station).
How hot do summers get in Perris, CA?
The average high peaks at 95 °F in August, with about 100 days a year at 90 °F or more.
What kind of soil does 92599 have?
The USDA soil survey maps Exeter at the center of ZIP 92599: sandy loam, well drained, pH about 7.0 (neutral).
Did spring come early in Perris, CA in 2026?
Spring leaf-out near 92599 came on Jan 19 in 2026, 6 days earlier than the 1991–2020 average (Jan 25), according to the USA National Phenology Network Spring Index.
What kind of onions grow in Perris, CA?
Intermediate onions: the longest day near 92599 is 14 h 24 min, so day-neutral types bulb best; long-day varieties may not bulb fully.