Garden Climate for Guatay & Pine Valley: 91931, 91962
Zone 8b · Last frost ~Apr 19 · Soil 57.3°F today (modeled) · See your place on the 2023 USDA zone map
ZIPs in this area
What differs between these ZIPs: elevation, soil temperature. Everything else on this page is the same for all of them. The page below shows 91931 (closest to the area's middle elevation).
| ZIP | Town | Elevation | Zone | Last frost | First frost | Chill hrs last season | Soil now |
|---|---|---|---|---|---|---|---|
| 91931 | Guatay | 4,008 ft | 8b | Apr 19 | Oct 27 | not enough data | 57.3°F |
| 91962 | Pine Valley | 4,066 ft | 8b | Apr 19 | Oct 27 | not enough data | 59.9°F |
Why grouped: these ZIPs use the same frost-date station (CA CUYAMACA HCN) and chill-hour station (not enough nearby data), share USDA zone 8b, sit in the same far inland band (distance to the ocean) and within the same 250 m (820 ft) elevation band.
Public NOAA/USDA data, updated 2026-10-16 18:57 UTC.
USDA Plant Hardiness Zone Map · Guatay focus
USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture. Accessed from https://planthardiness.ars.usda.gov/. Rendered unaltered from the PRISM Group, Oregon State University GIS data (https://prism.oregonstate.edu, accessed 15 Oct 2026) with official zone colors. Roads (TIGER/Line 2023 primary roads), place names (2023 Gazetteer) and state lines (2023 cartographic boundaries 1:500k) are drawn on top. Source: U.S. Census Bureau.
Frost dates for 91931
Earliest-risk fall date (10%): Oct 9.
NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) · CA CUYAMACA HCN (USC00042239) 15.8 km away 25 yrs of record · 633 ft higher than this ZIP
Newsletter · 91931
Frost alerts and planting reminders for 91931. Coming soon.
7-day forecast · High / Low / Rain / Frost / Wind
NOAA NWS api.weather.gov (SGX). Frost = low ≤32°F · High wind = gust ≥40 mph · 💧 = chance of precipitation and expected amount (NWS quantitative precipitation forecast; blank when NWS gives none) · Rain = chance ≥50%.
What to grow when · 91931
Calendar: San Diego County, mountains (900 m / ~3,000 ft and up). Planting months from University of Arizona Cooperative Extension Yavapai County Bulletin #51 'Yavapai County Vegetable Planting Dates' (an out-of-county analog; no San Diego-specific guide covers this area). Harvest months add typical days-to-harvest. This month also checks live soil temperature and the 7-day frost forecast. The harvest planner uses the same calendar. Rules: methodology.
Questions about 91931
What USDA hardiness zone is 91931?
ZIP 91931 (Guatay, CA) is in USDA zone 8b (15 to 20°F average annual extreme minimum), per the 2023 USDA Plant Hardiness Zone Map.
When is the last frost in 91931?
Based on NOAA 1991–2020 normals at Ca Cuyamaca Hcn (15.8 km away), the median last 32°F freeze is Apr 19. In 1 of 10 years it is after May 14. The median first fall freeze is Oct 27.
Nearby ZIP codes
Sources for this page
- Location: US Census Bureau 2023 Gazetteer, ZCTA internal point
- Zone: USDA Plant Hardiness Zone Map 2023, ZIP datasets (USDA ARS + PRISM Climate Group, Oregon State University)
- Frost: NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal freeze probabilities (32F) CA CUYAMACA HCN (USC00042239) 15.8 km away 25 yrs of record · 633 ft higher than this ZIP
- Forecast: NOAA National Weather Service api.weather.gov (7-day forecast + gridpoint wind gusts)
- Soil: Open-Meteo forecast API soil model (non-commercial terms)
- Chill: RuntimeError: not enough nearby data: no suitable hourly weather station within 25 km
- Raw data: /data/zip/91931.json