First Alert Weather In-Depth: The microclimate provided by Lake Ontario

ROCHESTER, N.Y. — We know the weather can vary from location to location and, as a result, Western New York has different microclimates.

This time of the year the most dramatic difference is the local temperature. A good example of this is the expected high temperature for a given day. Communities within a few miles of the Lake Ontario shoreline may find the temperature rising only into the low 50s, and this will likely include such towns as Sodus, North Webster, Hilton or North Irondequoit.

However, just a few miles to the south it seems to warm up dramatically and the difference in the thermometer can be as much as 20 or even 30 degrees. This is considered lake effect during the spring season.

Why does this happen? This time of the year as the sun is getting higher and higher in the sky and the land surface is heating-up pretty rapidly. The parcels of air directly above the ground get lighter and less dense. When that happens the air begins to rise, like a hot air balloon. But this is not happening to the air directly above Lake Ontario. Remember, the Lake Ontario water temperature this time of the year is only in the middle 40s and there is very little heating.

The air above the lake water is chilly, heavier and more dense. If the overall large scale wind flow is light, then then the dense, cool air has a natural tendency to push onshore. Interesting to note that during the nighttime hours the trend can be reversed because the land cools faster than the lake and it switches to an offshore breeze.

In the summer, this natural cooling can be a great benefit to folks living along the lakeshore. This is part of the reason why Seabreeze Amusement Park was built along the lakeshore as it was due to the cool breeze emanating from Lake Ontario — which is pretty smart considering there was no air conditioning back in 1871.