Short answer: California Climate Zone 10 covers the Inland Empire and inland San Diego County. The California Energy Commission assigns 171 ZIP codes to it, across 58 places including Riverside, San Bernardino, San Diego, Corona and Escondido. Use the table below or the ZIP code lookup to confirm a project's zone.
Title 24 climate zones are assigned by the California Energy Commission (CEC) by ZIP code, not by city limits. That is why a large city can appear in more than one zone, and why 3 of the places below also have ZIP codes in another zone.
Climate Zone 10 ZIP Codes by City
Source: the CEC's Building Climate Zones by ZIP Code table. Place names come from postal data and can differ from city limits. Your report always uses the zone for your project's exact address.
| City or place | ZIP codes in Zone 10 | Also in |
|---|---|---|
| Alpine | 91901, 91903 | — |
| Beaumont | 92223 | — |
| Bloomington | 92316 | — |
| Bonsall | 92003 | — |
| Bryn Mawr | 92318 | — |
| Calimesa | 92320 | — |
| Chino | 91708, 91710 | — |
| Chino Hills | 91709 | — |
| Chula Vista | 91914 | Zone 7 |
| Colton | 92324 | — |
| Corona | 92877, 92878, 92879, 92880, 92881, 92882, 92883 | — |
| Dulzura | 91917 | — |
| El Cajon | 92019, 92020, 92021, 92022 | — |
| Escondido | 92025, 92026, 92027, 92029, 92030, 92033, 92046 | — |
| Fallbrook | 92028, 92088 | — |
| Fontana | 92334, 92335, 92336, 92337 | — |
| Grand Terrace | 92313 | — |
| Guasti | 91743 | — |
| Hemet | 92543, 92544, 92545, 92546 | — |
| Highland | 92346 | — |
| Homeland | 92548 | — |
| Jamul | 91935 | — |
| Lake Elsinore | 92530, 92531, 92532 | — |
| Lakeside | 92040 | — |
| Loma Linda | 92350, 92354, 92357 | — |
| March Air Reserve Base | 92518 | — |
| Menifee | 92584 | — |
| Mira Loma | 91752 | — |
| Montclair | 91763 | — |
| Moreno Valley | 92551, 92552, 92553, 92554, 92555, 92556, 92557 | — |
| Murrieta | 92562, 92563, 92564 | — |
| Norco | 92860 | — |
| Nuevo | 92567 | — |
| Ontario | 91758, 91761, 91762, 91764 | — |
| Pala | 92059 | — |
| Patton | 92369 | — |
| Pauma Valley | 92061 | — |
| Perris | 92570, 92571, 92572, 92599 | — |
| Poway | 92064, 92074 | — |
| Quail Valley | 92587 | — |
| Ramona | 92065 | — |
| Rancho Cucamonga | 91701, 91729, 91730, 91737, 91739 | — |
| Redlands | 92373, 92374, 92375 | — |
| Rialto | 92376, 92377 | — |
| Riverside | 92501, 92502, 92503, 92504, 92505, 92506, 92507, 92508, 92509, 92513, 92514, 92515, 92516, 92517, 92519, 92521, 92522 | — |
| San Bernardino | 92401, 92403, 92405, 92406, 92407, 92408, 92410, 92411, 92413, 92415, 92418, 92423, 92427 | Zone 16 |
| San Diego | 92127, 92128, 92131, 92142, 92150, 92158, 92197, 92198, 92199 | Zone 7 |
| San Jacinto | 92581, 92582, 92583 | — |
| San Marcos | 92069, 92078, 92079, 92096 | — |
| Santee | 92071, 92072 | — |
| Spring Valley | 91976, 91977, 91978, 91979 | — |
| Sun City | 92585, 92586 | — |
| Temecula | 92589, 92590, 92591, 92592, 92593 | — |
| Upland | 91784, 91785, 91786 | — |
| Valley Center | 92082 | — |
| Wildomar | 92595 | — |
| Winchester | 92596 | — |
| Yucaipa | 92399 | — |
| Other ZIP codes | 91718, 91719, 91720, 91760, 91798, 92090, 92412, 92414, 92416, 92420, 92424 | — |
Why the Exact Zone Matters for Your Report
Title 24 is one statewide energy code, but the energy budget your design is compared against is calibrated to the climate zone, and several prescriptive requirements change by zone. If your ZIP code is split between zones, we confirm the zone from the project address before modeling. See Climate Zone 10 Title 24 requirements and how Title 24 calculations work.
Find Your Zone
Browse our city Title 24 pages for local information, or send your project address and we'll confirm the climate zone and prepare your report. See also: how climate zones affect a Title 24 report and the Climate Zone 10 overview.
← Back to the Climate Zone 10 overview · All climate zones
More Climate Zone 10 guides: zone overview · Title 24 requirements · Title 24 cost · ADU requirements.
The same topic in neighbouring zones: Climate Zone 9 and Climate Zone 11. Statewide: finding your climate zone.