Hail Index (Premium Layer)

The Hail Index provides hourly forecasts of hail probability to help users assess and manage the risk of hail events across North America.

🔒 This feature is part of Tomorrow.io’s premium offerings. For access, please contact your Tomorrow.io Account Team or sales@tomorrow.io.

Overview

• Forecast Window: Up to 48 hours ahead
• Update Frequency: Hourly
• Index Values:
  • 0 – Not probable
  • 1 – Probable

The Hail Index is available across the contiguous United States, Canada, and parts of northern Mexico.

Viewing the Hail Index on the Platform

To view hail probability forecasts:

1. Navigate to the Trends tab
2. Enable the Hail Potential layer
3. The index will be visualized in purple on the map, representing areas with forecasted hail risk

You can also configure hail-based insights and alerts for monitored locations to support proactive response.

Access via API

Developers can access the Hail Index using Tomorrow.io’s Weather API.

• Field name: hailIndex
• Visit the API documentation for full guidance on how to retrieve and apply this data

Need Help?

For assistance with using or integrating the Hail Index, contact your Account Team or reach out to support@tomorrow.io.