If you are looking for a tropical getaway, you have come to the wrong place. Seriously. Juneau is a rainforest. A temperate one, sure, but a rainforest nonetheless. When people ask what's the weather in juneau alaska, they usually expect a straightforward answer about snow and ice. Instead, they get a lesson in "Liquid Sunshine."
It rains. A lot.
Juneau sees about 230 days of precipitation a year. That is not a typo. If you visit, you aren't just likely to see rain; you are essentially guaranteed to encounter it. But here is the thing: the locals don't let it stop them. You’ll see people jogging, hiking, and even dining outdoors in a light drizzle like it’s perfectly normal. Because for them, it is.
Understanding the Microclimates of the Panhandle
The geography here is wild. You have the Gastineau Channel on one side and massive, jagged mountains on the other. This creates a funnel effect. You might be standing downtown in a light mist, but five miles away at the Mendenhall Glacier, it’s ten degrees colder and dumping snow.
This isn't just "Alaska weather." It's Southeast Alaska weather.
The Pacific Ocean acts like a giant thermostat. It keeps Juneau from getting as bone-chillingly cold as Fairbanks (where -40 is a real thing), but it also prevents it from ever getting truly hot. The "marine influence" means the temperature stays in a relatively tight band.
- Summer Highs: Usually 60°F to 65°F.
- Summer Lows: Around 50°F.
- Winter Highs: Hovering near 32°F to 35°F.
- Winter Lows: Dropping into the mid-20s.
Honestly, it’s the dampness that gets you. 35 degrees in Juneau feels way colder than 20 degrees in a dry climate. The moisture just seeps into your bones if you aren't wearing the right gear.
What's the Weather in Juneau Alaska Month by Month?
Timing is everything. If you show up in October, you’re hitting the peak of the rainy season. If you show up in May, you might actually see the sun for more than twenty minutes at a time.
💡 You might also like: What Time Is It In Yemen Now: Why This Tiny Detail Matters So Much
The "Dry" Spring (April - May)
I use the word "dry" very loosely here. May is historically the driest month, but it still gets plenty of showers. This is arguably the best time to visit if you want to avoid the massive cruise ship crowds that swarm the docks later in the summer. The mountains are still capped with heavy snow, the flowers are starting to pop, and the air feels crisp.
The Tourist Peak (June - August)
This is when the sun stays up forever. On the summer solstice in late June, you get over 18 hours of daylight. It never really gets pitch black; it just turns into a deep, velvety twilight for a few hours.
July is usually the warmest month. The record high is 90°F, set back in 1975, but don’t pack your bikini expecting a repeat. Most days, you’ll be perfectly comfortable in a flannel shirt and a light windbreaker. By August, the "rainy" switch starts to flip back on.
The Deluge (September - October)
September is beautiful because of the changing colors, but man, it gets wet. October is the wettest month of the year, averaging nearly 8 inches of rain at the airport (and often much more in the mountains). If you’re coming now, bring a serious raincoat. Not a "water-resistant" fashion jacket. A "rubberized, commercial-fisherman-style" raincoat.
The Long Dark (November - March)
Winter in Juneau is a moody masterpiece. It’s not just the cold; it’s the lack of light. In December, you’re looking at about 6 hours of daylight. The sun barely clears the mountain peaks before it starts heading back down.
Snowfall is unpredictable. Some years, the city gets buried under 100+ inches. Other years, it’s just "snain"—that miserable mix of snow and rain that turns the sidewalks into a slushy nightmare.
Packing Like a Local: The Three-Layer Rule
If you walk around Juneau in an umbrella, everyone knows you’re a tourist. Umbrellas are useless here because the wind comes off the channel sideways. You want a hood.
- The Base Layer: Synthetic or wool. No cotton. Cotton stays wet and makes you cold.
- The Insulation: A fleece or a "puffy" down jacket.
- The Shell: This is the most important part. It must be 100% waterproof.
Footwear matters too. If you plan on doing any hiking, get waterproof boots. The trails are basically glorified stream beds half the time. Xtratuf boots (the brown rubber ones) are basically the unofficial state shoe of Alaska for a reason. They work.
The Weird Stats Most People Miss
Did you know Juneau is in a temperate rainforest? That means it’s part of the Tongass National Forest, the largest in the U.S. All that rain is what makes the moss so green and the trees so massive.
The humidity is almost always high, usually hovering between 70% and 90%. While this is great for your skin, it means your wet clothes will never, ever dry if you hang them up in a room without a heater.
Also, watch out for the "Taku Winds." These are fierce, cold winds that blast down from the icefield and can reach hurricane speeds. They mostly happen in the winter and spring, and they can rattle the windows of downtown buildings like someone is trying to break in.
Real Advice for Your Trip
Don't check the 10-day forecast. It's almost always wrong. Or rather, it’s always the same: "Partly cloudy with a chance of showers." That is the default setting for the region.
Instead, look at the "Short Term Forecast Discussion" from the National Weather Service Juneau office if you want the real nerd-level details. They’ll tell you if an atmospheric river is headed your way or if a high-pressure ridge might actually give you a "bluebird day."
If you get a sunny day in Juneau, drop everything and go outside. Go to the top of Mount Roberts. Hike the West Glacier Trail. The locals call it "sun-shaming"—the act of making your friends feel guilty for being indoors when the weather is actually nice.
Actionable Next Steps:
- Invest in Gore-Tex: If you are buying gear for a trip, prioritize a high-quality waterproof shell over everything else.
- Check the Tides: If you're exploring the coast, the weather is only half the battle; the tide swings in Juneau can be 20 feet or more.
- Book May or June: For the highest statistical chance of seeing the sun and avoiding the August "rainy season" ramp-up, target the early summer window.
- Embrace the Grey: Lower your expectations for clear blue skies and you will have a much better time enjoying the misty, ethereal beauty that makes Southeast Alaska famous.