Mid-winter · Weather & things to do
San Juan Island in January
Little changes in San Juan Island from December: highs stay near 45°F (7°C), lows near 39°F (4°C), and about 5.8 in (147 mm) of rain falls.
With a comfort score of 37/100 (11th of 12), it's one of the toughest months, held back mainly by cloud cover.
- Avg high
- 45°F (7°C)
- Avg low
- 39°F (4°C)
- Rain
- 5.8 in (147 mm)
- Humidity
- 87%
- Cloud cover
- 83%
- Daylight
- ~8 h 31 min
- Comfort score
- 37/100 · Tough
What January feels like
It's cool, with highs near 45°F (7°C), so a proper jacket stays on most of the day.
Nights cool to an average low of 39°F (4°C).
Expect regular rain: about 5.8 in (147 mm) falls in the month.
Expect plenty of overcast days, with cloud cover near 83%.
Daylight is short, roughly 8 h 31 min mid-month, so start sightseeing early.
Plan around January
January is one of the lower-scoring months here; the best are June – September.
- Inside the wettest three-month stretch, November – January.
- Comfort holds steady from December (37 → 37/100).
- Our Puget Sound Islands route recommends May – Sep, so January falls outside its suggested window.
What to pack for January
- Insulated jackethighs only 45°F
- Rain jacket and waterproof shoesfrequent rain
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in San Juan Island in January
With 5.8 in of rain, these picks lean toward food, drink and places with a roof, with outdoor options when the weather breaks.
The Whale Museum
Small Friday Harbor museum on the Southern Resident orcas and local research.
Why now An indoor-leaning stop for a month with 5.8 in of rain.
Duck Soup
Long-running island restaurant using local produce and seafood.
Why now A sit-down stop to wait out showers in a month with 5.8 in of rain.
Roche Harbor
Historic marina village with a flag ceremony at sunset in summer.
San Juan Island Brewing Company
Brewpub two blocks from the ferry with pizzas and a patio.
American Camp
Open prairie and beaches from the 1859 Pig War, part of the national historical park.
Nearby in January
- Victoria in January~18 mi · highs 45°F, 5.8 in rain · similar daytime temperatures, about as wet
- Vancouver in January~52 mi · highs 41°F, 12.7 in rain · 2°C (4°F) cooler by day, wetter
- Olympic NP in January~57 mi · highs 32°F, 11.3 in rain or snow · 7°C (13°F) cooler by day, wetter
- Bainbridge Island in January~67 mi · highs 46°F, 6.9 in rain · similar daytime temperatures, 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 January: quick answers
Is January a good time to visit San Juan Island?
It's one of the tougher months here, scoring 37/100, held back mainly by cloud cover. The best months are June – September. Expect highs of 45°F (7°C) and 5.8 in (147 mm) of rain. Our Puget Sound Islands route recommends May – Sep, so January is outside its suggested window.
How cold is San Juan Island in January?
Average highs are 45°F (7°C) and average lows 39°F (4°C), making it the 2nd-coldest month by daytime highs.
Does it rain a lot in San Juan Island in January?
Yes: about 5.8 in (147 mm) of rain falls across January on average, the 2nd-wettest month of the year. The annual total is about 39.0 in (991 mm).
What should I pack for San Juan Island in January?
Bring insulated jacket (highs only 45°F), rain jacket and waterproof shoes (frequent rain) 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 January?
Bring the crew into one shared trip: vote on dates, build the day-by-day plan, split costs and share one packing list.