California Water Temperatures in the Northwest

Why travel to southern California when you can enjoy equally warm water temperatures?

Where should you head?   British Columbia's Strait of Georgia.

Let's start with a broad view of current eastern Pacific sea surface temperatures (SST).  Cool temperatures (blue) in the Gulf of Alaska and along the West Coast north of Santa Barbara.  Why?   Because summertime northerly winds result in upwelling of cool water below the surface.  You have to go south to Los Angeles before water temperatures rise into the the 60sF (green, 20C is 68F)

Zooming in closer, one sees the coastal upwelling and the warmer offshore.  But if you look even closer (in the NE corner) was will notice some warmer water (yellows and even oranges) in the Strait of Georgia, between Vancouver Island and the BC mainland.

Let's move ever closer.  Cold in the Strait of Juan de Fuca, but into the mid-60sF  within the central Strait of Georgia.   Warmer than Los Angeles!

So why is the Strait of Georgia so warm?  The topographic map  of the region (below) and the depth of waters of the Strait of Georgia  (also shown) give some hints.   The inner Strait of Georgia is isolated from the ocean and has weak tidal currents.  Furthermore, there are substantial areas where the water is shallow.

The result of reducing tidal action less movement of cool Pacific water into the Strait and less mixing of surface water, which can warm during the long summer days.   Such warming results in lighter water at the surface, which further reduces vertical mixing.   Thus, the water can warm into the upper 60s and occasionally into the lower 70s.  It is said that the warmest water north of Baja California is in Pendrell Sound, BC. (see map for location)

 Quite suitable for swimming without a wet suit!


Talk in Port Angeles on Wed. August 17th 

I will be talking in Port Angeles about the Future of the Pacific Northwest Under Global Warming at 6:30 PM on August 17th.  More information here.