# Weather alarm thresholds

AccuWeather weather alarms are determined using the daily forecasts for a location. An alarm exists for a location if the forecast weather meets or exceeds the following thresholds:

| Alarm Type               | Imperial Threshold | Metric Threshold |
| ------------------------ | ------------------ | ---------------- |
| Rain                     | 0.5 inch           | 12.7 mm          |
| Snow                     | 1 inch             | 2.54 cm          |
| Ice                      | 0.1 inch           | 0.254 mm         |
| Sustained Wind           | 30 mph             | 48 kph           |
| Wind Gust                | 40 mph             | 64 kph           |
| Thunderstorm Probability | 75%                | 75%              |