Mount Baker's next major eruption is most likely to send a column of ash several kilometres into the atmosphere and erupt viscous lava flows. Neither of these events constitute a significant hazard. However, because the mountain is capped by an estimated 2 km³ of glacial ice and snow, even minor eruptions could generate significant mudflows and floods. Depending on which valley these floods descended, cities in the eastern Fraser River valley (such as low-lying parts of Abbotsford) could be flooded. In addition, because the volcano is almost directly under flight paths into and out of Vancouver, British Columbia, even minor eruptions of ash constitute a significant hazard to aviation in southwestern Canada.

Larger, more devastating eruptions are known from Mount Baker's past. If the style of future eruptions at Mount Baker were to change from the smaller eruptions that have occurred over the past few hundred years, any future eruption could have a far more significant impact on southwestern British Columbia. An emergency preparedness exercise in January 1997 tested the ability of government and inhabitants of the Fraser River valley to cope with a significant volcanic event resulting from an eruption of Mount Baker. The exercise, referred to as 'Thunderbird 3', was run by the British Columbia provincial government in collaboration with other levels of government. Emergency preparedness personnel in communities in the Fraser River valley were asked to cope with significant accumulations of ash and with flooding of many low-lying parts of the valley. Exercises such as Thunderbird 3 are crucial for developing volcanic-hazard safety awareness and action plans in communities likely to be affected by future volcanic eruptions.