Maritime polar air masses are known for their cool and moist characteristics. When these air masses move into a region, they typically lead to overcast skies, light to moderate precipitation, and cooler temperatures.
The coolness comes from the original source of the air mass, which forms over cold ocean waters. As it travels, it picks up moisture, which can result in fog and cloudiness when it interacts with land. This moist air may lead to rain or snow depending on the temperature of the atmosphere it encounters.
In summary, expect cooler temperatures, cloudy skies, and increased chances of precipitation when a maritime polar air mass is present. This type of weather is often typical in coastal areas, especially during transitional seasons like fall and spring.