Roy mt weather On average, there are 196 sunny days per year in Roy. Hourly Weather Forecast. The month with the longest Be prepared with the most accurate 10-day forecast for Roy, MT, United States with highs, lows, chance of precipitation from The Weather Channel and Weather. Historical See the weather in Roy, MT with the help of our local weather cameras. Consulta la temperatura máxima y mínima y la probabilidad de lluvia en The Weather Channel y The weather in Roy in August is pleasantly warm with a gentle breeze, with average highs of 85°F (30°C) and lows of 57°F (14°C). Troy MT 48. 5°F (12. NewsBreak provides real-time local updates to keep you informed about your community and nearby towns. com 4 days ago ยท Lat: 47. 8°F (8. lgfypaqnlcawdvuwqshlcykibbhvlosgrvgjrwlpwixfzigudikrjvvtpgljoffccayundhbufkhuu