Does Clear Lake Freeze?

Clear Lake in Winter — Chill, But Not Frozen

People hear “California” and picture surfboards, palm trees, and year-round sun. But Clear Lake doesn’t fit that postcard image. Especially not in January.

Up here, winter feels like winter. The air gets crisp, mornings come with fog, and you’ll want something thicker than a hoodie if you’re outside before 9 a.m. Still, the lake has its own rhythm — and it’s not one that includes turning into an ice rink.

A lot of visitors ask if Clear Lake ever freezes. Locals? We don’t even think about it. But if you’re curious how cold it really gets up here, whether you’ll see snow, and just how icy that water feels… let’s break it down.

How Cold Does Clearlake, CA Get?

Clear Lake isn’t freezing, but it definitely gets cold enough to make you zip up your jacket. On winter mornings, it’s not unusual to see temperatures drop into the low 30s — especially overnight. Daytime highs usually hover in the 40s or 50s, depending on the month.

What surprises a lot of people is how quickly things warm up once the sun’s out. A chilly 35°F morning can turn into a pleasant 60°F afternoon if the skies are clear. That’s pretty standard for this part of Northern California.

It helps that the lake sits around 1,300 feet above sea level. Not high enough for serious mountain weather, but enough to feel very different from the coast or the Central Valley. And yes, you’ll see frost on rooftops and icy grass if you’re out early enough. Just don’t expect snowdrifts.

Does It Snow in Clear Lake?

Short answer: not often. But sometimes, yes — just enough to get excited, and then it’s gone.

Most winters, Clear Lake itself doesn’t see much snow. Maybe a light dusting once every few years, usually gone by midday. The kind of snow that barely sticks to the trees, melts off your car roof before you’ve finished your coffee, and makes you wonder if you imagined it.

If you’re hoping for a real snowy scene, head a little higher. Places like Cobb Mountain or Boggs Mountain, just a short drive from the lake, get snow more regularly. Enough to crunch under your boots and build a decent snowman — assuming you’re quick.

Locals usually don’t count on snow here. But when it happens, it’s a nice little surprise… followed by everyone posting the same five snow photos to Facebook.

If you’re not here for snow but still want to make the most of winter, check out these things to do around Clear Lake — plenty of quiet hikes, scenic drives, and cozy stops worth your time.

How Cold Is the Water in Clear Lake?

Winter water temperatures in Clear Lake usually hang around the low 40s (°F). Some years, it’ll dip into the upper 30s. That’s not quite ice-forming cold, but it’s enough to take your breath away if you decide to stick a toe in.

Unlike smaller ponds, the lake’s volume and depth help it retain a bit of warmth even when the air feels frosty. Water changes temperature more slowly than air, so even after a freezing night, the lake won’t suddenly turn into a giant slushie.

Clear Lake Water Temperature Throughout the Year

To give you some perspective, here’s a quick look at average surface temperatures by season:

Month	Avg Temp (°F)	Min Temp (°F)	Max Temp (°F)	Comfort
January	48.4	45.9	53.4	🧊 Cold
February	50.0	45.3	54.7	🧊 Cold
March	53.4	45.3	60.3	🧊 Cold
April	58.6	48.4	68.0	🧊 Cold
May	65.8	59.2	72.3	🧊 Cold
June	72.0	65.7	78.8	🌤️ Warm
July	77.7	72.3	82.9	🔥 Hot
August	77.9	71.1	81.9	🔥 Hot
September	74.7	69.1	80.1	🌤️ Warm
October	67.8	60.8	74.7	🧊 Cold
November	59.5	52.0	65.8	🧊 Cold
December	51.8	45.7	59.7	🧊 Cold

A slow, steady shift — no wild temperature swings, but you’ll feel the change as the seasons turn.

Deeper Waters Stay More Stable

If you were to dive down (which, please don’t in winter), you’d notice the temps stay more consistent. Deeper parts of the lake often hover in the mid-40s year-round. That stability helps prevent freezing and keeps the lake’s ecosystem running smoothly, even during cold snaps.

How Cold Is Too Cold to Swim in a Lake?

Technically, you can swim in just about any temperature. The real question is whether you’ll enjoy it — or regret everything five seconds in.

Most people start to feel uncomfortable in water under 70°F. That’s the line where a casual swim starts feeling more like a challenge. Below 60°F? You’re definitely in “why am I doing this” territory.

Here’s a general guide:

• Above 75°F — Comfortable for most swimmers.
  
• 70–75°F — Still fine, but might feel brisk at first.
  
• 60–69°F — Cold. You’ll adapt after a few minutes, but it’s not for everyone.
  
• 50–59°F — Very cold. Short swims only. Expect gasps and goosebumps.
  
• Below 50°F — Hypothermia risk increases fast. Unless you’re training for a polar bear plunge, maybe just enjoy the view.
  

Clear Lake in winter usually sits in the mid to upper 40s. That’s well into nope territory for swimming — unless you’re into cold exposure on purpose. Even in spring, the water might look nice, but your body won’t thank you for jumping in.

If you’re visiting outside of summer, bring a thermos and a kayak. Not a swimsuit.

So… Does Clear Lake Freeze?

Not really.

Clear Lake is big — over 68 square miles — and deep enough to resist freezing even during the coldest months. The surface might get chilly, and you’ll see frost along the shoreline some mornings, but the lake itself doesn’t turn to ice.

To fully freeze, you’d need weeks of sub-freezing temperatures day and night. That just doesn’t happen here. The lake has too much thermal mass, meaning it holds onto heat well into winter — not to mention its volcanic origin, which adds a bit of geothermal warmth under the surface. Even when the air dips into the 20s, the water below is still moving, still relatively warm, and not interested in turning solid.

Smaller ponds and shallow creeks around the area? Sure — you might catch a thin layer of ice on a cold morning. But Clear Lake? Not happening.

So, despite how brisk it gets up here, leave your skates at home. Pack a jacket, enjoy the quiet winter views, and let the lake do its thing — unfrozen, reflective, and still pretty magical.