How to Use TianWenTong's Stargazing Index? Tonight's Stargazing Forecast Guide

TianWenTong serves as a professional stargazing tool offering all-in-one astronomical services. It calculates stargazing indices based on Clear Sky Chart and ECMWF meteorological data. This guide explains how to use TianWenTong's stargazing index forecasts.

Where to Check the Stargazing Index?

1. Follow our WeChat official account through this article and access TianWenTong via the menu.
2. Directly scan the mini-program QR code below using WeChat:

How to Interpret the Stargazing Index?

For beginners, focus on the numerical value and rating. For example, "55%/Fair" in the image above.

提示

The Stargazing Index ranges from 0% (poorest) to 100% (best), considering weather conditions and lunar phases.

Index	Rating
<40%	Very Poor
40%~54%	Poor
55%~69%	Fair
70%~84%	Good
≥85%	Excellent

We recommend stargazing when the index reaches 70% or above for optimal conditions.

How Accurate Is the Stargazing Index?

All weather forecasts carry inherent uncertainty. Since meteorological data contributes to the index calculations, discrepancies may occur.

Generally:

• 24-hour forecasts are most reliable (except during typhoons)
• Accuracy decreases beyond 24 hours (max 3-day forecasts provided)
• Combining multiple forecast models improves reliability (switch forecast types in-app)

Detailed Meteorological Forecasts

Three forecast types are available below the main index:

相关信息

1. Clear Sky Chart developed by Dr. Ye Quanzhi
2. Enhanced Hourly Forecast optimized with ECMWF data
3. 15-Day Forecast powered by OpenWeather

Using Clear Sky Chart

Key features:

• Updates 4 times daily
• 3-hour forecast intervals
• Critical parameters: Cloud cover, Seeing, Transparency

Moon phase information appears on the right side:

Hourly Forecast Usage

Provides:

• 4 daily updates
• 1-hour granularity
• Intuitive visual interface

15-Day Forecast

Note: This forecast doesn't affect stargazing index calculations and updates twice daily.

3-Day Stargazing Index

Located below weather forecasts:

While less accurate than daily forecasts, this helps with advanced planning.

Additional Considerations

Moon Phase & Rise/Set Times

Check moonlight conditions:

• Avoid moonlit nights for deep-sky observations
• Find "Moonless Night" periods below the index
• Search "Super Moon" for detailed lunar info

Air Quality

Real-time AQI appears below the index:

Tap for detailed metrics:

Recommendations:

• Only stargaze when AQI is "Good" or "Excellent"
• Particularly crucial for northern China

Light Pollution

Light pollution levels appear in top-right capsules:

Recommendations:

• Bortle Scale 5 or darker for Milky Way visibility
• Use built-in Light Pollution Map

Satellite Imagery

Check real-time cloud cover:

Access via:

• Satellite map below 3-day index
• Floating menu icon

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Compiled by: TianWenTong / Mysterious Lao A