Weather in the Bristol Bay area tends to be cool, cloudy, and misty with frequent rain and wind. Day temperatures in the summer range between 50 and 60 degrees Fahrenheit while night temperatures may drop to 40 degrees Fahrenheit. The surface of the Alagnak freezes in the winter, but water continues to flow. Frozen overflow creates thin layers of dangerous ice which pose a hazard for those who attempt winter river travel. Whatever the season, weather conditions may prevent airplanes from flying in, so parties should be prepared for at least one extra day on the river. Wearing layers of clothing makes it easy to regulate your body temperature.