If you’re checking the hamlin new york weather because you’re planning a trip to the beach or just moving to Monroe County, you probably expect the standard "Upstate" experience. Gray skies. Some snow. Maybe a nice breeze off the lake.
But honestly? Hamlin is its own weird beast.
Living on the edge of Lake Ontario changes the rules of physics—or at least it feels that way when you’re standing on the shoreline at Hamlin Beach State Park. The lake is a massive heat sink. It’s a moisture engine. Basically, it’s a giant mood ring for the town. One day it’s a serene, blue paradise; the next, it’s throwing "ice volcanoes" at your feet.
The Lake Ontario Effect: More Than Just Snow
Most people think "Lake Effect" only matters in December. That's wrong. The lake dictates the hamlin new york weather every single day of the year.
In the spring, while people just ten miles south in Brockport are enjoying a 60-degree afternoon, Hamlin might be stuck in the 40s. We call it the "lake breeze." It’s basically a natural air conditioner that won’t turn off. If the water is still 38 degrees, any wind coming off that lake is going to feel like an ice bath.
But here is the trade-off.
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In the fall, that same water stays warm while the air turns crisp. This creates a "thermal blanket" effect. It actually keeps the first frost at bay longer than in the inland towns. Local apple growers around here love it. That extra week or two without a hard freeze is the difference between a bumper crop and a total loss.
Winter and the Legend of the Ice Volcano
Let’s talk about the snow. You've probably heard the horror stories about Buffalo, but Hamlin gets its fair share of the action too.
The winter of 2025-2026 has been a prime example of how volatile things can get. We see average lows hitting around 21°F in January, but the "feels like" temperature is the real killer. When those 30 mph gusts come off the water, the wind chill can easily dip into the negatives.
Then there are the ice volcanoes.
They aren’t actually volcanoes, obviously. When the lake starts to freeze, mounds of ice form along the shore. High waves smash against the ice shelf and shoot water up through holes in the ice. It freezes instantly. You end up with these massive, hollow cones that look like something from another planet. They are cool to look at, but seriously—stay off the ice. People fall through every few years because the shelf is way thinner than it looks.
Summer in Hamlin: The Hidden Paradise
If you can survive the "Big Gray" (the overcast stretch from November to May), the summer rewards you.
July is the peak. You’re looking at average highs of 76°F, which sounds mild compared to the sweltering heat of NYC or even Syracuse. That’s the magic of Hamlin. The lake keeps the "swelter" away. It rarely gets above 85°F. It’s perfect "windows down" weather.
- June: The water is still cold, so the beach is for sunbathing, not swimming.
- August: The lake has finally warmed up to the high 60s or low 70s. This is when the park is packed.
- September: My favorite time. The crowds leave, the water is still warm, and the sunsets over the lake turn a deep, bruised purple.
The cloud cover in August is the lowest of the year—only about 34% of the time is it overcast. Compare that to January, where it's gray 67% of the time. You have to soak up that Vitamin D while you can.
Precipitation: It's a Constant
Don’t forget your umbrella.
Hamlin gets about 30 to 32 inches of rain a year, plus about 65 inches of snow. It’s pretty evenly distributed. You don’t really have a "dry season" here. You just have "frozen precip" and "liquid precip."
Living with the Forecast
If you’re coming to visit, especially for a day at the beach, don't just check the general Rochester forecast. Check the marine forecast.
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The hamlin new york weather can vary wildly from what’s happening at the airport. If the marine forecast says "Small Craft Advisory" or predicts 6-foot waves, the beach is going to be windy and loud. If the wind is coming from the South, the water will be flat and the air will be warm.
Honestly, the best way to handle it is to dress in layers. Always. Even in July, once that sun goes down over the water, the temperature drops fast.
Next Steps for Your Visit:
- Check the National Weather Service marine forecast for the "Hamlin Beach to Sodus Bay" zone before heading to the shore.
- If you're visiting in winter, stick to the designated trails at Hamlin Beach State Park; the "ice volcanoes" are best viewed from a safe distance on the sand.
- Pack a windbreaker regardless of the season—the lake breeze is no joke.