Local zoning · Mendocino County

Mendocino County — Signage

Signage under the Mendocino County local zoning and planning code, with the controlling citations.

Ask a question free See coverage

Last reviewed: July 6, 2026

Overview

This page covers how signs are regulated in unincorporated areas of Mendocino County under the County’s zoning ordinance. Sign rules differ by geography: inland areas follow Chapter 20.184, the Coastal Zone outside the Town of Mendocino follows Chapter 20.476, and the Town of Mendocino Historical Review District has its own Chapter 20.712. Always determine which regulatory area your parcel is in before applying any standard and coordinate with Mendocino County Zoning and Mendocino County Overlay Districts.

Core rule: In unincorporated Mendocino County, inland on-site business signs are generally allowed in commercial and industrial settings with maximum heights and areas, while coastal and historic areas add stricter limits (including no internal illumination in the Town of Mendocino) and, in the historic district, Mendocino Historical Review Board review applies to virtually all signs (see § 20.712.015 and § 20.712.010).

How the County organizes sign rules

  • Inland: Chapter 20.184 – Sign Regulations (content-neutral, countywide inland framework; last comprehensively updated in 2024) sets general rules, on‑site limits, off‑site allowances, and temporary sign procedures in unincorporated inland areas. See § 20.184.005 and § 20.184.010.
  • Coastal Zone (outside Town of Mendocino): Chapter 20.476 – Signs governs coastal parcels with tailored on‑site, off‑site temporary, and temporary on‑site rules, plus strong view/illumination controls. See § 20.476.025, § 20.476.020, and § 20.476.030.
  • Town of Mendocino Historical Review District: Chapter 20.712 – Sign Regulations applies within the historic town limits; off‑site signs are prohibited, signs are small and wood where feasible, illumination is indirect only, and all signs are subject to Mendocino Historical Review Board (MHRB) review. See § 20.712.010 and § 20.712.015.

Use Mendocino County Development Standards and Mendocino County Design Review pages as companions when siting signs near driveways, corners, or within design‑review areas, and consult Mendocino County Historic Preservation for historic procedures.

Quick limits by area (decision snapshot)

Area (unincorporated) Wall signs Freestanding signs Roof signs Total site sign area cap Illumination Code Reference
Inland (Title 20.184) Up to 1 sq ft per linear foot of street frontage; max 160 sq ft; 25 sq ft minimum allowance Max height 25 ft; max 64 sq ft per sign Up to 5 ft above roof; max 64 sq ft 128 sq ft total; up to 160 sq ft if no freestanding or roof signs Allowed if source not visible; no flashing/strobe § 20.184.030(B)(1)-(3), (D); § 20.184.010(F)
Coastal (Title 20.476) Up to 1 sq ft per foot of frontage; max 80 sq ft; 25 sq ft minimum Max height 15 ft; max 40 sq ft per face Up to 5 ft above roof; max 40 sq ft 40 sq ft total; up to 80 sq ft if no freestanding or roof signs Indirect only; no internal; no flashing § 20.476.025(H)(1)-(3), (J); § 20.476.025(E)-(F)
Town of Mendocino (Title 20.712) One sign per business when sufficient; each sign ≤6 sq ft; total per site ≤12 sq ft Generally ≤6 ft high; directory signs up to 80 inches (8 ft if parallel), 36 in. wide, each panel 216 sq in Not emphasized; attached signs must not extend above eave/roof/parapet Site total ≤12 sq ft (excludes directory/menu per Chapter 20.760) Indirect only; no internal; neon prohibited; no flashing/moving; wood where feasible; MHRB review § 20.712.015(B)-(F), (I)-(L); § 20.712.010

Countywide essentials (in plain English)

  • Property owner consent is required and all signs must comply with federal/state/local law and content‑neutral rules. See § 20.184.010(A)-(E).
  • No moving parts, wind‑propellers, flashing, strobing, or variable‑intensity lighting. See § 20.184.010(F)-(G) (inland) and § 20.476.025(F) (coastal).
  • Maintain visibility triangles at corners/driveways and respect district setbacks. See § 20.184.010(H).
  • How area/height are measured (inland): frontage adds up across all frontages; measure area by enclosing letters or using height×width; two‑sided back‑to‑back counts once if within 45° and ≤3 ft apart. See § 20.184.045.

Inland — Chapter 20.184 Sign Regulations (unincorporated areas, inland)

Purpose and scope

  • Encourages effective communication while preventing clutter and hazards via content‑neutral standards. See § 20.184.005.

Where it applies

  • Unincorporated inland areas (outside the Coastal Zone and outside the Town of Mendocino).

Typical permitted sign situations

  • Business identification for commercial/industrial properties; select informational signs countywide.

Key dimensional standards

  • On-site signs (where allowed): Applies to all commercial/industrial zones, to lots where commercial/industrial uses are permitted, and to lots with legal nonconforming commercial/industrial uses. See § 20.184.030(A).
    • Wall: up to 1 sq ft per foot of frontage (max 160 sq ft; at least 25 sq ft allowed), no higher than the roofline. See § 20.184.030(B)(1).
    • Freestanding: ≤25 ft height; ≤64 sq ft per sign; cannot project into rights‑of‑way. See § 20.184.030(B)(2).
    • Roof: ≤5 ft above roof; ≤64 sq ft; no projection beyond exterior walls. See § 20.184.030(B)(3).
    • Total site sign area: ≤128 sq ft, or ≤160 sq ft if no freestanding or roof signs. See § 20.184.030(D).
  • Off-site permanent: Allowed only in Limited Industrial, General Industrial, or General Commercial, not within 300 ft of a residential zone fronting the same street and not in public ROW; ≤300 sq ft per face; freestanding ≤35 ft; one per lot; does not count toward the host parcel’s on‑site sign area. See § 20.184.015.
  • Off-site directional to residences (where addressing is inadequate): Up to three signs, each ≤2 sq ft, showing only name and directional info. See § 20.184.020.
  • Temporary signs (≤90 days) by Administrative Permit: ≤32 sq ft; number, time limit, and placement set in the permit; no illumination for off‑site temporary signs. See § 20.184.025.

Other notable inland allowances (selected)

  • “No trespassing/parking”: ≤4 sq ft each. See § 20.184.040(A).
  • Awnings/canopies: ≤4 sq ft per side. See § 20.184.040(B).
  • Identification plaques: two per building; each ≤2 sq ft. See § 20.184.040(C).
  • Temporary window signs: ≤25% of window area. See § 20.184.040(D).
  • Agricultural products (on‑premises): one sign; ≤8 sq ft; ≤8 ft height. See § 20.184.040(F).
  • Multiple dwellings/clubs: one freestanding + one building‑mounted, each ≤8 sq ft. See § 20.184.040(G).
  • Civic/educational/charitable institutions: one sign, total ≤40 sq ft, freestanding ≤8 ft. See § 20.184.040(H).
  • For sale/lease and construction site signs: up to two per frontage; ≤32 sq ft per frontage; freestanding ≤8 ft; remove within 10 days of closeout. See § 20.184.040(I).
  • Community identification: one per approach route; ≤50 sq ft per face; ≤20 ft height. See § 20.184.040(J).

Exempt (no sign permit under this chapter)

  • Official and safety signs; court notices; house numbers; flags/emblems; commemorative plaques; signs not intended to be viewed from streets; maintenance and copy changes; non‑advertising murals; state‑required fuel price panels. See § 20.184.035.

Coastal Zone (outside Town of Mendocino) — Chapter 20.476 Signs

Purpose and scope

  • Coastal on‑site signs are tightly tailored to protect views and coastal character, with specific size/height caps and illumination controls. See § 20.476.025.

Where it applies

  • Unincorporated Coastal Zone parcels outside the Town of Mendocino Historic District.

Key dimensional standards

  • Wall: no higher than roofline; ≤1 sq ft per foot of frontage; max 80 sq ft; minimum 25 sq ft allowed. See § 20.476.025(H)(1).
  • Freestanding: ≤15 ft height; ≤40 sq ft per sign face. See § 20.476.025(H)(2).
  • Roof: ≤5 ft above roof; ≤40 sq ft. See § 20.476.025(H)(3).
  • Total site sign area: ≤40 sq ft, or ≤80 sq ft if no freestanding or roof signs. See § 20.476.025(J).
  • Illumination/motion: where used, lighting must be indirect and low‑key; no internal illumination; no flashing/moving. See § 20.476.025(E)-(F).
  • Home occupation/cottage industry: one non‑illuminated sign ≤2 sq ft, attached flat or visible through a window. See § 20.476.025(G).
  • Protect views: do not block public ocean views. See § 20.476.025(D).

Temporary signs

  • Temporary on‑site: real estate signs up to 16 sq ft per frontage; short‑term window banners up to 15% of ground‑floor window area; opening pennants; political signs (timing/size rules). See § 20.476.030(A)-(D).
  • Temporary off‑site (residential developments/special events): by Coastal Development Administrative Permit; up to five signs; ≤32 sq ft; ≤90 days; height per district; nonprofits visible <22 days are exempt from CDP. See § 20.476.020(A)-(B).

Exemptions and legacy signs

  • Certain official/directional/safety signs are exempt; see § 20.476.035(A).
  • Nonconforming signs: see § 20.476.040 and continuation § 20.476.045.

Town of Mendocino Historical Review District — Chapter 20.712 Sign Regulations

Purpose and scope

  • Protects historic character and public views; discourages neon, oversized, off‑site, and excessive temporary signs. See § 20.712.005.

Where it applies

  • Within the Town of Mendocino Historic District (coastal). This is both a coastal and historic overlay; MHRB review applies to nearly all signs.

Key standards (highlights)

  • Off‑site signs prohibited. See § 20.712.010.
  • Building‑attached signs must not extend above eave/roof/parapet; freestanding signs generally ≤6 ft; directory signs: max height 80 inches (8 ft if parallel to the road), 36‑inch width, 216 sq in per business panel. See § 20.712.015(A)-(B), (F)(1)-(3).
  • Only one sign per business when one suffices; each sign ≤6 sq ft; total of all freestanding + attached signs ≤12 sq ft per site (directory/menu/“open/closed” regulated elsewhere). See § 20.712.015(E).
  • Visitor accommodations: on‑site only; wood material “where feasible”; design must harmonize with historic context. See § 20.712.015(C)-(D), (G).
  • Illumination: indirect, low‑key, limited to business hours; no internal illumination; neon prohibited; no flashing/moving. See § 20.712.015(I)-(J).
  • Home occupations/cottage industries: ≤2 sq ft total. See § 20.712.015(K).
  • MHRB review: all signs (including indoor self‑contained lighted signs visible from walkways) require MHRB review; exceptions may be granted if consistent with historic character. See § 20.712.015(L).

Temporary/other

  • Temporary real estate: ≤3 sq ft per frontage; remove within 15 days of sale/lease. See § 20.712.020(A).
  • Banners/pennants for openings (short duration); political signs removed within 15 days; nonprofit special‑event signs visible <22 days are exempt from coastal permit. See § 20.712.020(B)-(D).
  • Exemptions (official notices, numbers, etc.) and coastal‑permit exemptions for building‑attached signs under state coastal rules are listed in § 20.712.025.
  • Nonconforming/illegal/abandoned sign cleanup and amortization (generally five years or MHRB approval): § 20.712.030–.045.

Practical notes

  • If your project also involves site work, coordinate sign placement with Mendocino County Parking and corner visibility rules. Inland siting must keep “areas of unrestricted visibility” clear at corners and driveways. See § 20.184.010(H).
  • Exceptions/relief: Inland administrative adjustments for specific sign types are possible, and formal relief lives under Mendocino County Variances and Exceptions. See § 20.184.040 (noting Administrative Permit in § 20.184.065, referenced in caps) and Chapter 20.192 (processing).
  • Legacy signs: also see Mendocino County Nonconforming Uses for broader concepts; sign‑specific nonconforming provisions are embedded in the coastal and historic chapters cited above.

Checklist

  • Confirm your parcel’s regulatory area: inland, Coastal Zone (outside Town), or Town of Mendocino Historic District.
  • Identify your base use context (commercial/industrial vs. residential/civic) and applicable sign type.
  • Compute allowable area and height correctly; add up all frontages if applicable (inland). See § 20.184.045.
  • Verify setbacks and corner/driveway visibility clearances. See § 20.184.010(H).
  • Check illumination/material restrictions (coastal and Town: no internal illumination; Town favors wood). See § 20.476.025(E)-(F); § 20.712.015(D), (I).
  • If proposing off‑site signage, confirm it is allowed in your zone (inland: Limited/General Industrial or General Commercial) and meets distance/height/area caps. See § 20.184.015.
  • For temporary signs, obtain the correct Administrative Permit if required and follow size/duration rules. See § 20.184.025 and § 20.476.020–.030.
  • If in the Town of Mendocino, plan for MHRB review and small, low‑key, on‑site signage only. See § 20.712.010–.015.
  • For any deviation, consult Mendocino County Design Review and Mendocino County Variances and Exceptions.

Risks & Ambiguities

Issue Why it matters What to verify
Mixing inland and coastal standards Different caps and illumination rules; coastal often stricter Confirm regulatory area before sizing/lighting a sign (inland § 20.184.030, coastal § 20.476.025)
Historic district review Most signs require MHRB approval and smaller sizes Whether the site is inside the Town boundary; apply § 20.712.015 and off‑site prohibition § 20.712.010
Off‑site sign eligibility Allowed only in specific inland zones; extra setbacks and proximity rules apply Zone is Limited/General Industrial or General Commercial; distance to residential; height/area/number per § 20.184.015
Area calculations for irregular or two‑sided signs Miscalculation can push you over caps Use frontage‑based totals and two‑sided/back‑to‑back counting in § 20.184.045 (inland)
Window and temporary signs Short‑term allowances are limited by percent area and days Apply window percentage and removal timelines (inland § 20.184.040(D), (I); coastal § 20.476.030)
Illumination type Internal illumination is barred in Town of Mendocino and constrained in coastal areas Indirect‑only rules in § 20.476.025(E) and § 20.712.015(I); inland source‑shielding per § 20.184.010(F)

Plain-English Summary

If you’re in unincorporated Mendocino County, first figure out if you’re inland, on the coast, or inside the Town of Mendocino. Inland business signs can be taller and larger, but they’re still capped by frontage and total area; coastal signs are smaller and must be low‑key, and Town of Mendocino signs are the most modest and must pass historic review. Off‑site signs are tightly limited inland and banned in the Town; temporary signs have strict size and time limits everywhere.

Source References

Sources

Retrieved passages

  • Mendocino County Zoning Code High relevance
  • Mendocino County Zoning Code (§ 48) High relevance
  • Mendocino County Zoning Code (§ 48) High relevance
  • Mendocino County Zoning Code (Chapter 20.760.) High relevance
  • Mendocino County Zoning Code (Section 30610) High relevance
  • Mendocino County Zoning Code (§ 48) High relevance
  • Mendocino County Zoning Code (Section 20.720.020.) Medium relevance
  • Mendocino County Zoning Code (§ 2) Medium relevance

Cited sections

Frequently asked questions

Are illuminated LED or internally lit cabinet signs allowed in unincorporated Mendocino County?

Inland, signs may be illuminated if the light source isn’t directly visible and there’s no flashing or strobing. In the Coastal Zone, illumination must be indirect and low‑key; and in the Town of Mendocino, internal illumination and neon are prohibited. Always confirm your area and apply the stricter standard. See § 20.184.010(F), § 20.476.025(E)-(F), and § 20.712.015(I).

How big can my business sign be inland on a commercial lot?

Inland wall signs may be up to 1 square foot per linear foot of street frontage (max 160 sq ft; minimum 25 sq ft allowed). A freestanding sign can be up to 25 feet tall and 64 sq ft; total site sign area is typically capped at 128 sq ft (160 sq ft if you have no freestanding or roof signs). See § 20.184.030(B)-(D).

Can I place an off-site sign for my business along a county road?

Inland, permanent off‑site signs are limited to Limited Industrial, General Industrial, or General Commercial properties, with distance/setback, height (≤35 ft), and area (≤300 sq ft) limits, and they can’t intrude into public ROWs. One off‑site sign per lot is allowed and it doesn’t count toward the host parcel’s on‑site area. Town of Mendocino prohibits off‑site signs. See § 20.184.015 and § 20.712.010.

What are the rules for real estate signs?

Coastal on‑site real estate signs may be up to 16 sq ft per frontage and must be removed within 15 days of sale/lease. In the Town of Mendocino, each temporary real estate sign is limited to 3 sq ft per frontage with the same 15‑day removal window. Inland “for sale/lease” signs are treated as temporary on‑site signs with size/height/removal limits (e.g., 32 sq ft per frontage; ≤8 ft tall; remove within 10 days). See § 20.476.030(A), § 20.712.020(A), and § 20.184.040(I).

How is sign area calculated for oddly shaped or two-sided signs?

Inland, you enclose irregular shapes in up to eight straight lines or use standard formulas; back‑to‑back faces within 45° and ≤3 ft apart count once. The total allowable area is based on total street frontage for the lot. See § 20.184.045.

Are banners and pennants allowed?

Yes, but with limits. Inland temporary signs need an Administrative Permit and are capped at 32 sq ft; permit conditions set duration and number. Coastal areas allow opening banners and similar devices with short time frames; the Town of Mendocino also allows grand‑opening streamers briefly. See § 20.184.025, § 20.476.030(C), and § 20.712.020(B).

Do I need historic review for a sign in the Town of Mendocino?

Yes. Most signs—indoor self‑contained lighted signs visible from public walkways included—require Mendocino Historical Review Board review. The MHRB can grant exceptions if they don’t harm historic character. See § 20.712.015(L).

Can coastal signs block ocean views if they meet size limits?

No. Coastal standards prohibit blocking public views of the ocean regardless of size conformance; signs must be sited to preserve view corridors. See § 20.476.025(D).

More in Mendocino County code

Ask about any Mendocino County property

Get a cited, plain-English answer on Mendocino County zoning, setbacks, FAR, ADUs and permits — for any address.

Start Free Trial

More Mendocino County zoning topics

Mendocino County Zoning

Mendocino County Land Use

Mendocino County Development Standards

Mendocino County Parking

Mendocino County Design Review

Mendocino County Overlay Districts

Mendocino County Historic Preservation

Mendocino County Nonconforming Uses

Mendocino County Variances and Exceptions

Mendocino County Landscaping and Screening

Mendocino County overview