Sea Level Rise

The Humboldt Bay area is experiencing the fastest rate of relative sea level rise on the West Coast. That's because tectonic activity is causing the ground beneath the bay to sink at the same rate that the ocean is rising. According to the California Ocean Protection Council's 2024 Science & Policy Update, sea level in the Humboldt Bay area is expected to rise approximately 1.5-2 feet above 2000 levels by 2060 and 3.9-5.5 feet by 2100.

The primary impacts from sea level rise are increases in flooding, erosion, and rising groundwater. Sea level rise will expand areas vulnerable to flooding during major storms, as well as in the rare but catastrophic event of a major tsunami. The term 100-year flood is used as a standard for planning, insurance, and environmental analysis. But these extreme storms are happening with increasing frequency, in part due to rising seas. Sea level rise will cause more frequent—and more damaging—floods to those already at risk and will increase the size of the coastal floodplain, placing new areas at risk to flooding. To view sea level rise scenarios for the Humboldt Bay area, visit NOAA's 2022 Sea Level Rise Viewer and go to the local scenario for the North Spit.

NEW! Now you check out our interactive map of two sea level rise scenarios for the Humboldt Bay Area! Featured are scenarios showing 1- and 2-meters above Year 2000 water levels. For many years, these have been static maps with no simple way for the public to examine points of interest. Now, people wondering if their neighborhood is at risk can zoom in on locations and see street names, etc.

A Slow Motion Flood: Rapid Sea Level Change on the North Coast

2/15/12

Rapid sea level rise in the next 100 years could affect more than coastal residents may think.

The rise could change the environment of the Arcata Marsh, create prime salmon habitat or affect property values, said local scientist Michael Furniss.

Rough Waters for Sea Level Rise Planning

7/29/11

What do Bay Area airports and some big Silicon Valley companies have in common? They sit right on the edge of San Francisco Bay, where sea level rise is expected to have a big impact by the end of the century.

That may seem far in the future, but state agencies are preparing for climate change now by writing new rules for construction along the bay’s shoreline. As you can imagine, developers and environmentalists aren’t exactly seeing eye to eye.

California King Tide Photo Gallery — and how to submit yours!

The California Coastal Commission's King Tide Photo Project features photos from the Humboldt Bay area and across the state. Anyone can upload photos online or via a smartphone app. Click HERE to upload yours. You can check out King Tide photos from across the state at this interactive photo gallery.

Wondering about good spots to view the King Tides around Humboldt Bay? Visit our Humboldt Bay King Tide Photo Project.

Stormy King Tides, January 2-3, 2026

This winter's last set of King Tides will arrive this Friday and Saturday, January 2-3. The current tides are nearly a foot higher than predicted, and with more rain in the forecast and winds from the south, these tides are likely to be even higher than they were in early December.

BE EXTREMELY CAUTIOUS when viewing these King Tides! Under these conditions, you may encounter eroding shorelines, rapidly rising water, and flooded roadways. With recent storms, the ground is so saturated that in low-lying areas, there's nowhere for more stormwater runoff to go. As always, wear bright colors so drivers can see you, and never drive through flooded roadways. Photo of the Samoa Bridges on Dec. 4, 2025 by J. Kalt.

King Tide Photo Initiative: December 4-6, 2025

The highest tides of this winter (known as King Tides) are predicted this Thursday, Friday, and Saturday, December 4-6. To get involved, all you need is a camera or a smartphone. You can upload your photos to the California King Tide Photo Project, which is a great opportunity to contribute to a long-term dataset, while helping inform residents and decision makers about the need to plan for the coming changes to our natural and built environments.

Please USE EXTREME CAUTION when viewing the King Tides! Wear bright colors near roads and be very cautious of rising water, eroding shorelines, and flooded roadways. Tides may be much higher than predicted depending on wind, rain, etc.