Citizen scientists needed to document king tides this winter

Do you have a digital camera or camera phone? If so, help local and regional researchers capture this year's king tides!

King tide at English Camp on San Juan Island

Join Friends of the San Juans and king tide volunteers from your community and across the globe to document the year's highest tides by taking photos of your favorite local shorelines.

A "king tide" is the highest predicted high tide of the year at a given coastal location. These highest tides occur naturally when the sun and the moon align, increasing the gravitational pull on the Earth's oceans. This only happens one to two times per year.

By sharing your pictures you will help the community see the future. Visualizing sea level rise can help us understand future impacts and how to plan for them. Friends of the San Juans will compile and share these pictures as one part of our ongoing efforts to promote habitat friendly sea level rise adaptation throughout the islands.

King tides are predicted for the mornings of December 5th through 9th and January 3rd through 7th and volunteers are needed to capture images from across our island community. Images with some recognizable feature such as a road, unique rock or tree, a recognizable public place or building are the most effective. If possible, take a photo from the same vantage point at an average high tide or even a low tide. Send your pictures to with information on when and where the pictures were taken.

2017-18 Winter King Tides:

Date Approximate Time* Predicted High Tide**



December 4, 2017 6:30am 8.5
December 5, 2017 7:00 am 9
December 6, 2017 8:00 am 9
December 7, 2017 9:00 am 9
December 8, 2017 10:00 am 9
December 9, 2017 10:30 am 9
December 10, 2017 11:00 am 8.5
December 21, 2017 8:00 am 8.5
December 22, 2017 9:00 am 8.5
December 23, 2017 9:30 am 8.5
January 3, 2018 7:00 am 9
January 4, 2018 8:00 am 9
January 5, 2018 8:30 am 9
January 6, 2018 9:00 am 9
January 7, 2018 10:00 am 9


*Note: times are approximate for Friday Harbor station, anytime from 1 hour before to 1 hour after approximate time appropriate for field photographs.

**Note: tidal elevations are NOAA predicted (not observed) tides.  Additional factors such as low barometric pressure, wind waves, and/or the shape of a beach can increase tidal elevations above predicted levels.

Always remember - your safety is more important than an image, so use caution in high wave or high water events.

For more information about king tides and sea level rise in the islands visit


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