Mid-autumn · Weather & things to do
San Juan Island in October
San Juan Island cools off: highs slip to 56°F (13°C), from 65°F in September, with lows of 48°F (9°C) and about 4.3 in (109 mm) of rain.
Our comfort score puts it mid-table at 64/100, 6th of 12.
- Avg high
- 56°F (13°C)
- Avg low
- 48°F (9°C)
- Rain
- 4.3 in (109 mm)
- Humidity
- 83%
- Cloud cover
- 70%
- Daylight
- ~10 h 32 min
- Comfort score
- 64/100 · Good
What October feels like
Days are mild at around 56°F (13°C): comfortable for walking all day, with a layer for the evening.
Nights cool to an average low of 48°F (9°C).
Some rain is likely, about 4.3 in (109 mm) in the month, so pack for a shower or two.
Plan around October
October sits mid-table; the best months are June – September.
- The year's biggest cool-down: highs drop 5°C (9°F) from September.
- Comfort slips from 91/100 in September to 64/100.
- Our Puget Sound Islands route recommends May – Sep, so October falls outside its suggested window.
What to pack for October
- A warm layer for eveningslows near 48°F
- Packable rain jacket or umbrellaabout 4.3 in of rain
- Comfortable walking shoesmost picks involve some walking
What to do in San Juan Island in October
October is good outdoor weather here, so these picks lean toward the open air.
American Camp
Open prairie and beaches from the 1859 Pig War, part of the national historical park.
Why now October scores 64/100 for comfort, good conditions for being outside.
English Camp
British garrison site with restored buildings and a Young Hill hike.
Why now Highs near 56°F and 4.3 in of monthly rain make this an easy outdoor pick.
The Farm at Krystal Acres
Working alpaca farm in the island's west valley, with pastures to walk and a barn shop of alpaca-wool goods.
Why now One to do outside while the weather is on your side.
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.
Nearby in October
- Victoria in October~18 mi · highs 56°F, 4.3 in rain · similar daytime temperatures, about as wet
- Vancouver in October~52 mi · highs 57°F, 9.2 in rain · similar daytime temperatures, wetter
- Olympic NP in October~57 mi · highs 44°F, 7.8 in rain · 7°C (12°F) cooler by day, wetter
- Bainbridge Island in October~67 mi · highs 59°F, 4.9 in rain · 2°C (4°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 October: quick answers
Is October a good time to visit San Juan Island?
It's middling, scoring 64/100. The best months are June – September, at up to 95. Expect highs of 56°F (13°C) and 4.3 in (109 mm) of rain. Our Puget Sound Islands route recommends May – Sep, so October is outside its suggested window.
How cold is San Juan Island in October?
Average highs are 56°F (13°C) and average lows 48°F (9°C), making it the 6th-warmest month by daytime highs.
Does it rain a lot in San Juan Island in October?
Some: about 4.3 in (109 mm) of rain falls across October on average, the 4th-wettest month of the year. The annual total is about 39.0 in (991 mm).
What should I pack for San Juan Island in October?
Bring a warm layer for evenings (lows near 48°F), packable rain jacket or umbrella (about 4.3 in of rain) and comfortable walking shoes (most picks involve some walking).
More on San Juan Island
Planning San Juan Island in October?
Bring the crew into one shared trip: vote on dates, build the day-by-day plan, split costs and share one packing list.