Sun Altitude Calculator · Sunrise/Sunset Times | Solar Position Query Tool
Accurately calculate solar position (altitude, azimuth) at any time based on sun altitude angle, display sunrise/sunset/solar noon times. Automatically get your current location, pure local computation, privacy secure.
After granting location permission, the system will automatically calculate the sun altitude angle for your location
💡 If no time is selected, defaults to 12:00 noon for sun altitude calculation
👈 Get location and click Calculate
Grant location permission to view the sun altitude angle for your current location
Sun Altitude Calculator · User Guide & Features
📌 What is Sun Altitude Angle?
Sun Altitude Angle refers to the angle between the sun's rays and the local horizon. When the sun altitude is 90°, the sun is directly overhead; when it is 0°, the sun is on the horizon. The larger the altitude angle, the stronger the solar radiation received by the ground, the higher the temperature, and the shorter the shadow.
Sun Azimuth Angle refers to the angle between the projection of the sun's rays on the horizontal plane and true north (clockwise direction). 0° is north, 90° is east, 180° is south, and 270° is west.
📊 Feature Details
- 🌞 Sun Altitude Angle — The angle of the sun relative to the horizon at the query time.
- 🧭 Sun Azimuth Angle — The directional orientation of the sun, used to determine the sun's specific position in the sky.
- 🌅 Sunrise/Sunset Times — The moment when the sun's upper edge touches the horizon (considering atmospheric refraction).
- 🌞 Solar Noon & Noon Altitude — The moment when the sun crosses the local meridian, which is the highest sun altitude of the day.
- 🌅 Dawn/Dusk (Civil Twilight) — The period when the sun is 0°~6° below the horizon.
🔢 Calculation Principle
This tool is based on the suncalc astronomical computation library, using precise astronomical formulas to calculate solar position:
Sun Azimuth = arctan2(sinH, cosH × sinφ − tanδ × cosφ)
Where φ = geographic latitude, δ = solar declination, H = hour angle. Sunrise/Sunset is defined as the moment when the sun's upper edge is tangent to the horizon considering atmospheric refraction (sun altitude approximately -0.833°).
📖 How to Use This Tool?
- Get Location — Click "Get My Current Location" and grant browser location permission.
- Select Date — Choose the date you want to query, defaults to today.
- Select Time (Optional) — Choose a specific time, defaults to 12:00 noon if not selected.
- Click Calculate — The system will display sun altitude angle, azimuth angle, sunrise/sunset times, etc.
- Advanced Feature — Click "Manual Latitude/Longitude Input" to enter coordinates manually for queries.
⚠️ Important Notes
- Timezone: Results are displayed based on your device's local timezone, consistent with local actual time.
- Accuracy: suncalc uses high-precision astronomical algorithms with errors typically within 1-2 minutes.
- Privacy Protection: This tool is implemented purely on the frontend; all calculations are done locally in your browser, and location information is not uploaded to any server.
- High Latitude Regions: Sunrise/sunset times may appear abnormal during polar day/night periods, which is normal.