It’s cooler near the lake season. This is the time of the year when the chilly Lake Michigan water cools the air above it. When the wind blows from the east, the lake-cooled air moves inland and leads to lower daytime temperatures than people near the lake might prefer.

The temperatures near the lake depend of the strength and direction the wind is blowing, how close to the lake you are, and the time of the year.

When there is a strong east wind, the cooler air can be blown as far as 20 miles inland. That doesn’t happen frequently, but it can happen. It does get modified along the way, so it still won’t be quite as cool that far inland as it will be right at the shore.

If the east wind is light, the cool air may only be pushed a mile or two inland.

When the wind blows from the west, it prohibits the lake cooled air from moving inland, so lakeshore areas tend to be just as warm as inland areas.

What about when there is no wind at all? This also leads to the cooler air over Lake Michigan moving inland. When the sun warms the air over the land, that air begins to rise. The air out over the lake then moves inland to "replace" the air that has risen.

The temperature of the air over the lake also warms as the summer goes on because the lake water warms up. While a strong east wind in April may keep temperatures in just the 40s at the lakeshore, the same east wind in August would lead to readings in the 60s.