Washington · BLI
San Juan Islands weather this week
San Juan Islands scores 8.3 out of 10 and has no genuinely clear day in the next 7.
The model gives this week 8.3 out of 10 because it is warm and largely rain-free, and those are the two things the score measures. It is not measuring sunshine. With 0 genuinely clear days and 7 dull ones, expect grey skies. We are showing you the number and the contradiction rather than only the number.
7 cloudy / 0 wet days, no clear days in 7 — Cool, grey, and dry — overcast all week, peaks around 74°F
The next 7 days in San Juan Islands
Every number below is the forecast we hold, rendered as text — nothing here is drawn on a canvas or filled in by JavaScript. The rain figure is the highest chance across all 7 days (2%), not the lowest, because the worst number is the useful one.
Booking window Thu 13 Aug–Sat 15 Aug: 8.2/10 for those days alone. The 7-day outlook score (8.3) covers the full table below and includes days outside that window.
| Day | High | Low | Rain chance | Sky | Day score |
|---|---|---|---|---|---|
| 74°F | 52°F | 1% | Overcast cloudy | 8.5 Cloudy but warm & dry |
|
| 72°F | 54°F | 2% | Fog cloudy | 7.0 Cloudy but warm & dry |
|
| 72°F | 55°F | 2% | Overcast cloudy | 8.5 Cloudy but warm & dry |
|
| 72°F | 55°F | 1% | Overcast cloudy | 8.5 Cloudy but warm & dry |
|
| 72°F | 55°F | 0% | Overcast cloudy | 8.5 Cloudy but warm & dry |
|
| 68°F | 54°F | 2% | Overcast cloudy | 8.1 Cloudy and dry |
|
| 69°F | 53°F | 1% | Overcast cloudy | 8.2 Cloudy but warm & dry |
How this week got its score
- 7 forecast days: 0 clear/mainly clear, 0 partly cloudy, 7 overcast, 0 wet (fog/drizzle/rain/showers), 0 stormy.
- Trimmed mean of day scores 8.4 × 0.55 = 4.60
- Worst day drag: worst day is 7.0 × 0.25 = 1.75 - one bad day cannot be averaged away.
- Longest consecutive run of good days (≥7.0) is 7/7 = 100% coverage × 0.20 = 2.00
- Best single day is 8.5 but it only counts through the trimmed mean - a lone great day cannot carry the window.
- Advertised 3-day window (2026-08-13→2026-08-15) scores 8.2 on its own.
- Legacy gate counted 5/7 days as "perfect sun"; this model counts 0 genuinely clear.
The full model, including why a single great day cannot rescue a bad week, is on the methodology page.
Getting to San Juan Islands
The nearest airport we price is BLI. From New York City that is about 5h 15m in the air out of SWF, 2371 miles. Flight times from 55 other departure metros are on the search page.
Where to stay in San Juan Islands
We hold no live hotel rates for San Juan Islands right now, so there is nothing honest to show here. Rates return as soon as the supplier does — the refresh state is on system status.
So, should you go?
San Juan Islands scores 8.3 out of 10 and has no genuinely clear day in the next 7. If sunshine is the reason you are travelling, pick somewhere else this week — the full list is sorted by genuinely clear days, so the top of it is where to look.
Forecast data from Open-Meteo, last refreshed 2026-08-14T05:01:09.686221Z. Hotel names and rates come from LiteAPI and change constantly; the rate shown is the rate we held at refresh time, not a quote. Scores are forecasts, not guarantees, and the whole model is published on our methodology page.