Each spring and summer, especially from April through July, the Bay Area experiences some of its lowest tides of the year. These “minus tides” happen when several natural cycles line up. The biggest factor is the alignment of the sun and moon. Around new and full moons, their gravitational pull combines to create stronger “spring tides,” which means higher highs and lower lows.

In late spring, this effect is amplified by the tilt of the Earth and the sun’s position relative to the equator. During this time, the sun is more directly aligned with the Earth, which strengthens its influence on ocean water. When this solar effect stacks on top of the moon’s pull, it produces especially low tides.

Local conditions in the San Francisco Bay can make these lows even more noticeable. Seasonal winds, atmospheric pressure, and the shape of the coastline and Bay can all push water out more efficiently during these cycles.

The result is those dramatic low tides you see in spring, when shorelines stretch far beyond their usual limits and tidepools, mudflats, and Bay habitats are briefly exposed.

The graphic on the left illustrates:

Spring Tide top image. When the sun, moon, and Earth line up (new or full moon), their gravitational forces combine → stronger tides (higher highs, lower lows). A spring tide is a tide with the greatest difference between high and low water levels. It occurs when the Earth, moon, and sun are aligned (during a new moon or full moon), so their gravitational forces combine and create higher high tides and lower low tides than usual.

Neap Tide lower image. When the sun and moon are at right angles, they partially cancel each other out → weaker tides (less extreme highs and lows). A neap tide is a tide with the smallest difference between high and low water levels. It occurs when the sun and moon are at right angles relative to the Earth (during the first and third quarter moons), so their gravitational forces partially cancel each other out. As a result, high tides are lower than usual and low tides are higher than usual, creating a more moderate tidal range.

At the Bulb there are several opinions as to "when is the tide too low to swim at the Bulb." My personal cut-off is a -0.80 ft. Where to go at low tide? Some folks will launch from his Lordships. I prefer to switch to a dawn patrol schedule and skirt the low tide.

For 2026 here are the lowest tides in Berkeley / Albany:

April 20, 2026:       -1.22 ft @ 9:30 a.m.
May 18, 2026:       -1.71 ft  @ 8:56 a.m.
June 16, 2026:      -1.75 ft  @ 8:16 a.m.
July 14, 2026:       -1.48  ft  @ 7:14 a.m.
August 11, 2026:   -0.99 ft @ 6:11 a.m.