Birch Bay — Water Temperature, Sea Conditions & Trends

Water Temperature: Daily Trends, Historical Records, and Forecast

⚠️ As of today, the minimum water temperature ranges from 54°F (12°C) to 60°F (15°C). The water is significantly warmer, and swimming becomes possible for most people. However, caution may still be required for prolonged stays in the water, as extended exposure can cause discomfort. This is a suitable temperature range for short swims and for those accustomed to cooler water. For more comfortable swimming, it is recommended to use proper gear.

It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.

Water Temperature Chart Over the Last 30 Days

Water temperature in Birch Bay has risen over the last week and month. Currently, the sea water at this location is slightly warmer than average for this day in previous years.

According to our forecast, Water temperature in Birch Bay will be 12.9°C in the next 7 days. See the table below for daily data for the upcoming week.

Table of Daily Sea Temperature Data

Annual Water Temperature Overview by Month

Monthly Water Temp Ranges

30°C

25°C

20°C

15°C

10°c

5°C

0°C

Annual Water Temperature Trend

Birch Bay sits on the Salish Sea in northwest Washington near the Canadian border and is a broad, shallow inlet that warms more than exposed open-coast waters but remains characteristically cool year‑round. Seasonal surface temperatures typically run from about 6–8 °C in winter, rise through spring to roughly 8–12 °C, and reach their warmest in mid to late summer, commonly around 12–18 °C with peak days sometimes nearing the upper end in July and August. Autumn sees a steady cooldown, with surface readings often falling back into the 10–12 °C range before dropping again to winter lows. Local temperatures vary with tides, wind, recent weather and the shallow shoals along the beach, so conditions at the shoreline can be modestly warmer than readings a short distance offshore.