Title 24 Reports in Monterey County

The valley is the corridor

The Salinas Valley runs inland from Monterey Bay, and that opening is what carries cool marine air a long way into the county. It is the reason zone 3 covers not only the coast — Monterey, Carmel, Pacific Grove, Seaside, Big Sur — but also Salinas itself, some distance from the water.

Zone 3 accounts for 22 of the 31 ZIP codes we derive for the county. Zone 4 picks up further inland and to the south, where the marine influence weakens: the upper Salinas Valley around King City and the areas beyond it.

Why an inland town can still be coastal

This is the useful thing about Monterey County. Distance from the ocean is a poor guide here, because the valley's orientation matters more than the mileage. A town that feels inland can sit in the coastal zone because the air reaches it along the valley floor.

Which is precisely why the ZIP check rather than the map is the reliable method — geography that looks obvious on a map gives the wrong answer in this county more often than in most.

What changes between the two

Zone 3 is mild and marine, with modest cooling loads. Zone 4 is warmer inland, and cooling starts to matter in a way it does not on the coast. Agricultural and light industrial buildings in the southern valley are assessed on different assumptions from a hospitality project on the peninsula.

Example ZIP codes and their zones

Derived from the Energy Commission's ZIP-to-climate-zone table, with county membership taken from the U.S. Census Bureau's 2020 ZCTA-to-county relationship file:

• Climate zone 3 — 93901, 93905, 93940, 93950, 93955 and 17 more
• Climate zone 4 — 93450, 93927, 93928, 93932 and 5 more

ZIP codes that cross the county line

A ZIP code is a postal boundary, not a county boundary, and several here fall on both sides of one. Where that happens we do not treat the county as settling the question:

• 95004 — about 56% within Monterey County, the remainder in San Benito 44%
• 93930 — about 81% within Monterey County, the remainder in San Benito 19%
• 93426 — about 82% within Monterey County, the remainder in San Luis Obispo 18%

For an address in one of these, the climate zone still comes from the ZIP code, which is assigned by the Energy Commission regardless of the county line. What the split affects is which jurisdiction issues the permit — worth confirming before a submittal.

Finding the zone for your own project

The zone is set by the project's location and confirmed from the ZIP code against the Energy Commission's published table — not from the county name and not from the nearest large town. Because Monterey County contains more than one zone, that check decides which set of numbers a report is written against.

Give us the project address and we determine the zone as part of preparing the report. It is the first thing established, because every insulation, glazing and equipment figure downstream depends on it.

City and unincorporated permitting

A project inside a city's limits is permitted by that city. A project on unincorporated land is permitted by the county instead, and the two can run different submittal processes even where the energy requirements are identical. The California Energy Code is statewide — what changes locally is the climate zone the site falls in and how the jurisdiction wants the compliance documents presented.

Climate zones in Monterey County

Monterey County contains California climate zones 3 and 4. The zone drives the insulation, glazing and equipment performance a report has to demonstrate, and it is confirmed from the project ZIP code against the Energy Commission's published table.