A summer of record-breaking heat and what comes next

Last winter, Lake Winnipesaukee hit a troubling milestone, its shortest ice-cover period on record. For both locals and visitors, it was a clear reminder that our climate is changing. The ripple effects were hard to miss, the Pond Hockey Classic had to move its rinks from Meredith Bay to Lake Waukewan, the World Championship Sled Dog Race in Laconia was canceled for the second year in a row, and those familiar villages of bob houses dotting the big lake were nowhere to be seen.

While the loss of winter recreation stings, the changes go deeper than what we see on the surface. It’s not just about how we enjoy the lake — these shifts are affecting the delicate balance that keeps Lake Winnipesaukee’s ecosystem healthy.

This past summer brought even more extremes. New Hampshire saw its hottest summer on record, with El Niño playing a role. According to the National Oceanic and Atmospheric Administration, the outlook shows above-average temperatures and rainfall predicted for the rest of the year. And it wasn’t just here — August 2024 was the hottest month globally in 175 years of climate records.

So, what does this all mean for us in the Lakes Region? Sure, it’s nice to have these warm, sunny days lingering into fall. More time for boating, hiking, and getting outside. But, it feels a little off, doesn’t it? These late September heat waves are a sign that something bigger is happening. It’s not the crisp fall weather we’re used to. And while extending the boating season into October might seem like a win, warmer water temperatures could disrupt the natural rhythms the lake relies on, including the critical lake turnover process.

Turnover happens when cooler surface water mixes with the deeper layers, redistributing oxygen and nutrients throughout the lake. But with shorter ice cover and longer warm seasons, that process is getting thrown off balance. If turnover is delayed or weakened, it can lead to low oxygen levels in deeper waters, creating dead zones where fish and other aquatic life can’t survive. Plus, warmer water means more nutrients stay in the mix, fueling algae growth and putting extra stress on the lake’s ecosystem.

NOAA’s forecast for warmer temperatures through the end of 2024 makes it clear that our climate is changing, and it’s affecting Lake Winnipesaukee. The shifts in seasonal patterns — warmer falls, shorter winters, earlier ice-outs — are changing how we use the lake, and it’s reshaping the lake’s ecosystem.

Local conservation efforts, such as monitoring water quality, controlling invasive species, and reducing stormwater runoff are crucial steps in safeguarding our lake. However, these actions alone won’t be enough. We need to take a broader view and think bigger. Long-term management strategies, including sustainable usage practices and proactive watershed management planning, are essential in ensuring that the lake we cherish remains healthy and vibrant for generations to come.

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Bree Rossiter is the conservation program manager for the Lake Winnipesaukee Association. She manages the water quality monitoring program, cyanobacteria monitoring initiatives, the Winni Blue/LakeSmart program, and assists with watershed management planning efforts. Bree can be reached at brossiter@winnipesaukee.org. The Lake Winnipesaukee Association is a nonprofit dedicated to protecting the water quality and natural resources of the lake and its watershed. To learn more, visit winnipesaukee.org.