August weather forecast and climate
Montana, USA

August is a beautiful summer month in Montana as most of the state registers day temperatures in the 70°F (21.1°C) to 90°F (32.2°C). Summers are dry as the humidity hardly touches 45% in most of the state. August has an average of 24 sunny days in which the sunshine averages for 9 hours a day. West Glacier averages between 47°F (8.3°C) to 79°F (26.1°C) in the northwest, Butte 44°F (6.7°C) to 80°F (26.7°C) in the southwest, Bighorn Lake 56°F (13.3°C) to 88°F (31.1°C) in south-central, while Miles City in eastern Montana is the warmest with 58°F (14.4°C) to 87°F (30.6°C).
Rainfall subsides by August and rarely goes over 1" (25mm) to 1.5" (38mm) in the majority of the state.
While light clothing is usually sufficient during the days, the nights require layers due to the drop in temperatures. It is an excellent idea to carry an insect repellent during the dry summer, as insects are common in the prairie.