How We Calculate Visibility

Our visibility forecasts combine real-time meteorological data with specialized algorithms designed for landmark viewing. Here's complete transparency on our methodology.

The 0-100 Visibility Score

Every forecast includes a visibility score from 0 (completely obscured) to 100 (perfect viewing conditions). This score represents the probability you'll have clear, unobstructed views of the landmark.

Score Range	Status	What to Expect
90-100	Excellent	Perfect conditions, crystal clear views. Best time to visit for photography.
70-89	Good	Clear visibility expected. Minor haze possible but won't block views.
50-69	Fair	Limited visibility. Partial views likely through clouds or haze.
0-49	Poor	Landmark likely obscured by clouds, rain, or heavy haze. Consider rescheduling.

Calculation Formula

Our visibility score is calculated using a weighted formula based on four primary atmospheric factors:

1. Visibility Distance

40% Weight

The maximum distance at which objects can be clearly seen, measured in kilometers. This is the most critical factor for distant landmark viewing.

Scale: 0-10km = Poor | 10-30km = Fair | 30-50km = Good | 50km+ = Excellent

Mt. Fuji requires 60km+ visibility from Tokyo viewpoints, 30km+ from nearby areas like Kawaguchiko.

2. Cloud Cover

30% Weight

Percentage of sky covered by clouds at various altitudes. Clouds directly blocking the landmark's elevation are weighted more heavily.

Scale: 0-20% = Excellent | 20-50% = Good | 50-80% = Fair | 80-100% = Poor

For Mt. Fuji (3,776m elevation), we analyze cloud cover at multiple altitude bands to determine if the peak is obscured. View live Mt. Fuji visibility forecast to see this scoring in action.

3. Precipitation Probability

20% Weight

Likelihood of rain, snow, or fog. Even light precipitation significantly reduces visibility distance and creates atmospheric haze.

Scale: 0-10% = Excellent | 10-30% = Good | 30-60% = Fair | 60-100% = Poor

Any precipitation above 30% probability substantially lowers the visibility score.

4. Relative Humidity

10% Weight

Atmospheric moisture content creates haze even on "clear" days. High humidity is why summer visibility is poor despite sunny weather.

Scale: 0-40% = Excellent | 40-60% = Good | 60-80% = Fair | 80-100% = Poor

Winter's low humidity (30-40%) creates the crisp, clear air ideal for Mt. Fuji viewing. Summer humidity (70-90%) causes persistent haze.

Combined Formula:

Visibility Score = 
  (Visibility Distance × 0.40) + 
  (Cloud Cover Score × 0.30) + 
  (Precipitation Score × 0.20) + 
  (Humidity Score × 0.10)

Each component is normalized to a 0-100 scale before applying weights. The final score represents the overall probability of clear landmark visibility.

Data Sources

We source weather data from professional meteorological services with global coverage and high accuracy:

Weather Data Provider

Professional weather API services aggregate data from satellites, ground stations, and atmospheric models to provide comprehensive forecasts.

• Update frequency: Every 15 minutes
• Forecast range: 10 days ahead
• Geographic resolution: 1km precision
• Parameters: Visibility, cloud cover, precipitation, humidity, wind, temperature

Live Camera Feeds

We integrate 12+ live webcam streams from established sources around Mt. Fuji to provide real-time verification of forecast accuracy.

• Sources: Official tourism boards, local municipalities
• Locations: Kawaguchiko, Hakone, Tokyo, and more
• Update frequency: Real-time streaming

Validation & Accuracy

We continuously validate our predictions against actual visibility outcomes using live camera feeds and historical data analysis.

How We Improve Accuracy:

✓Cross-reference with live cameras: Compare predicted scores with actual visibility captured on webcams
✓Seasonal pattern analysis: Track visibility trends across months and years to identify patterns
✓Time-of-day optimization: Adjust scoring based on when visibility is historically best (6-8 AM)
✓User feedback integration: Learn from visitor reports to refine predictions

Known Limitations

We believe in transparency about what our forecasts can and cannot predict:

Forecast Accuracy Decreases Over Time

Like all weather predictions, accuracy is highest for the next 24 hours (85%+ accurate) and decreases for longer-range forecasts. Days 7-10 should be considered rough estimates for planning purposes only.

Mountain Weather is Variable

Conditions can change rapidly, especially in mountainous terrain. A score of 80 means "very likely visible" but isn't a guarantee. Always check updated forecasts and live cameras before traveling.

Local Microclimates

Our forecasts cover regional conditions. Specific viewing locations may have slightly different conditions due to elevation, local geography, or urban heat effects.

Nighttime Visibility

Our scoring currently assumes daytime viewing. Mt. Fuji is not visible in darkness regardless of weather conditions (score shows 0 at night). Night photography during full moons is possible but not yet scored separately.

How to Use Our Forecasts

1.Check the current Mt. Fuji visibility score to see if conditions are favorable right now
2.Review "Best Viewing Times" to find optimal hours today (usually early morning)
3.Use the 10-day forecast to plan trip dates in advance, targeting days with 70+ scores
4.Verify with live cameras before traveling to confirm real-time conditions match predictions
5.Have backup plans for scores below 70, as visibility may be limited

Questions About Our Methodology?

We're committed to transparency and continuous improvement. If you have questions about our calculations or suggestions for improvements, please reach out.