Sea level rise · Humboldt County, CA
Sea level rise
Visualize sea level rise exposure with this snapshot. Consider incorporating this data into all community planning strategies. In many communities, rising sea levels are already increasing the impacts of high tide flooding and storm surge events.
People at Risk
Rising population numbers exacerbate potential flooding risk; impacts can be even greater when social vulnerability factors (age, income, capabilities) are involved, as these citizens may not be able to adequately prepare and respond.
(1,564 people) of Humboldt County’s total population lives in areas exposed to just 2 ft of sea level rise. As is already the case in many parts of the country, these areas are the first to experience impacts.
Residents exposed at each increment of sea level rise.
Residents exposed at each increment of sea level rise: data table
| Category | 2 ft | 4 ft | 6 ft | 8 ft | 10 ft |
|---|---|---|---|---|---|
| Population | 1,161(1,564) | 2,419(2,760) | 3,998(4,231) | 5,274(5,449) | 6,605(6,842) |
| Aged 65 and over | 244(330) | 460(538) | 721(762) | 898(941) | 1,090(1,144) |
| Below the poverty line | 343(441) | 681(775) | 1,104(1,160) | 1,446(1,469) | 1,743(1,773) |
Flooded Facilities Can't Provide Critical Services
Fire and police stations. Hospitals. Shelters. These facilities play a central role in response and recovery. Understanding future exposure can help reduce damages and the conditions that make these services unavailable.
(0 of 163 facilities) of Humboldt County’s critical facilities are in areas exposed to just 2 ft of sea level rise. These areas are the first to experience impacts.
Facilities exposed at each increment of sea level rise.
Facilities exposed at each increment of sea level rise: data table
| Category | Total | 2 ft exposed | 4 ft exposed | 6 ft exposed | 8 ft exposed | 10 ft exposed |
|---|---|---|---|---|---|---|
| Schools | 84 | 0(0) | 0(0) | 0(0) | 0(0) | 0(0) |
| Police stations | 8 | 0(0) | 0(0) | 0(0) | 0(0) | 0(0) |
| Fire stations | 65 | 0(0) | 0(0) | 1(1) | 3(3) | 3(3) |
| Medical facilities | 6 | 0(0) | 0(0) | 0(0) | 0(0) | 0(0) |
Being Underwater Is Not a Good Business Plan
Flood-related losses of services, revenues, and salaries can hit a community hard.
(1,425 jobs) of Humboldt County’s jobs are in areas exposed to just 2 ft of sea level rise.
Jobs in areas exposed at each increment of sea level rise.
Jobs in areas exposed at each increment of sea level rise: data table
| Category | Ocean-connected | Additional, in low-lying areas |
|---|---|---|
| 2 ft | 697 jobs | 728 jobs |
| 4 ft | 2,465 jobs | 238 jobs |
| 6 ft | 4,824 jobs | 53 jobs |
| 8 ft | 6,305 jobs | 44 jobs |
| 10 ft | 7,619 jobs | 61 jobs |
Creating a Better Future: Yes, It Can Be Done
Make it a goal: more natural areas (wetlands, forests, parks, dunes, etc.) to absorb floodwaters and protect the community, and less development in flood-prone areas. Consider not only today’s floodplain, but also the floodplain extent projected for the future.
(8.3 of 26.9 square miles) of the land inundated in Humboldt County at 2 ft of sea level rise would be natural: wetland or upland.
Land cover inundated at each increment of sea level rise.
Land cover inundated at each increment of sea level rise: data table
| Category | Wetlands | Upland | Other |
|---|---|---|---|
| 2 ft | 7.7 sq mi | 0.6 sq mi | 18.6 sq mi |
| 4 ft | 9.3 sq mi | 1.1 sq mi | 23.7 sq mi |
| 6 ft | 10.7 sq mi | 1.7 sq mi | 28.5 sq mi |
| 8 ft | 11.8 sq mi | 2.3 sq mi | 32.7 sq mi |
| 10 ft | 12.7 sq mi | 2.9 sq mi | 36.2 sq mi |
When Is the Time to Act? Now!
Because a number of factors are involved, sea level rise projections are often expressed as scenarios. For projects involving structures with a long lifespan or where a loss would be catastrophic (power plants, ports, hospitals), the higher sea level rise scenarios should be considered. For projects with a shorter lifespan (bike paths, golf courses, parks), lower sea level rise scenarios may be appropriate.
Projections at the North Spit gauge, by scenario
Feet above 2000, in 2050 and 2100
Year each increment is reached
| Sea level rise | Intermediate | Intermediate-High | High |
|---|---|---|---|
| 2 ft | 2072 | 2060 | 2055 |
| 4 ft | 2101 | 2084 | 2074 |
| 6 ft | 2132 | 2105 | 2090 |
| 8 ft | after 2150 | 2130 | 2105 |
| 10 ft | after 2150 | after 2150 | 2121 |
Data, methods and citation
- Snapshot
- 2026-10-22
- Methodology
- Version 1. What changed: https://seachangeatlas.org/county-profiles/about/changelog/#methodology-changelog
- Tide gauge
- North Spit (OPC 2024, Appendix 2)
- Scenarios
- Intermediate, Intermediate-High, High
Recommended citation. California Sea Change Atlas. (2026, October 22). Humboldt County coastal county profile: Sea level rise. https://seachangeatlas.org/county-profiles/county/humboldt/2026-10-22/sea-level-rise/
| Source | Period covered | Retrieved |
|---|---|---|
| Census ACS 5-year estimates (2020–2024) https://www.census.gov/programs-surveys/acs/data.html | 2024 | 2026-10-22 |
| Census 2020 tabulation blocks (TIGERweb) https://tigerweb.geo.census.gov/arcgis/rest/services/Census2020/Tracts_Blocks/MapServer | 2020 | 2026-10-22 |
| NOAA Sea Level Rise Viewer inundation extents https://coast.noaa.gov/slrdata/ | 2026 | 2026-10-22 |
| USGS National Structures Dataset https://data.usgs.gov/datacatalog/data/USGS:db4fb1b6-1282-4e5b-9866-87a68912c5d1 | 2026-07-30 | 2026-10-22 |
| LEHD LODES8 workplace area characteristics https://lehd.ces.census.gov/data/lodes/LODES8/ca/wac/ | 2023 | 2026-10-22 |
| NOAA C-CAP regional land cover https://coast.noaa.gov/digitalcoast/data/ccapregional.html | 1996-01-01 to 2021-12-31 | 2026-10-22 |
| California Ocean Protection Council, State of California Sea Level Rise Guidance: 2024 Science & Policy Update, Appendix 2 https://opc.ca.gov/wp-content/uploads/2024/05/California-Sea-Level-Rise-Guidance-2024-508.pdf | 2024 | 2026-10-22 |