Early spring · Weather & things to do
San Juan Island in March
San Juan Island edges warmer than February, with highs of 49°F (9°C), lows of 41°F (5°C) and about 4.2 in (106 mm) of rain.
Our comfort score puts it mid-table at 50/100, 8th of 12.
- Avg high
- 49°F (9°C)
- Avg low
- 41°F (5°C)
- Rain
- 4.2 in (106 mm)
- Humidity
- 82%
- Cloud cover
- 79%
- Daylight
- ~11 h 34 min
- Comfort score
- 50/100 · Fair
What March feels like
Cool days top out near 49°F (9°C), better for brisk walks than lingering outside.
Lows average 41°F (5°C).
Showers are part of the month, adding up to about 4.2 in (106 mm).
Expect plenty of overcast days, with cloud cover near 79%.
Plan around March
March sits mid-table; the best months are June – September.
- Comfort holds steady from February (48 → 50/100).
- Our Puget Sound Islands route recommends May – Sep, so March falls outside its suggested window.
What to pack for March
- Insulated jackethighs only 49°F
- Packable rain jacket or umbrellaa shower or two is likely
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in San Juan Island in March
A mixed month: these picks balance outdoor stops with indoor fallbacks.
The Whale Museum
Small Friday Harbor museum on the Southern Resident orcas and local research.
Why now An indoor-leaning stop when highs sit around 49°F.
Duck Soup
Long-running island restaurant using local produce and seafood.
Why now A warm sit-down stop when highs sit around 49°F.
Roche Harbor
Historic marina village with a flag ceremony at sunset in summer.
American Camp
Open prairie and beaches from the 1859 Pig War, part of the national historical park.
Whale watching from Friday Harbor
Boat tours to find orcas, humpbacks and minke whales in Haro Strait.
Nearby in March
- Victoria in March~18 mi · highs 49°F, 4.2 in rain · similar daytime temperatures, about as wet
- Vancouver in March~52 mi · highs 46°F, 10.0 in rain · 2°C (3°F) cooler by day, wetter
- Olympic NP in March~57 mi · highs 34°F, 8.8 in rain or snow · 8°C (15°F) cooler by day, wetter
- Bainbridge Island in March~67 mi · highs 52°F, 5.4 in rain · 2°C (3°F) warmer by day, wetter
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
San Juan Island in March: quick answers
Is March a good time to visit San Juan Island?
It's middling, scoring 50/100. The best months are June – September, at up to 95. Expect highs of 49°F (9°C) and 4.2 in (106 mm) of rain. Our Puget Sound Islands route recommends May – Sep, so March is outside its suggested window.
How cold is San Juan Island in March?
Average highs are 49°F (9°C) and average lows 41°F (5°C), making it the 5th-coldest month by daytime highs.
Does it rain a lot in San Juan Island in March?
Some: about 4.2 in (106 mm) of rain falls across March on average, the 5th-wettest month of the year. The annual total is about 39.0 in (991 mm).
What should I pack for San Juan Island in March?
Bring insulated jacket (highs only 49°F), packable rain jacket or umbrella (a shower or two is likely) and comfortable walking shoes (most places below are best reached on foot or with short walks).
More on San Juan Island
Planning San Juan Island in March?
Plan it together in TripsCircle: one itinerary, one shared packing list and costs split as you go.