Do I really need expensive gear for just a city trip?

Yes. Copenhagen, Stockholm, and Oslo get sudden downpours and wind. Cheap rain gear fails when you need it most. You'll be miserable in cotton when it's 8°C and raining.

What if the weather is nice when I arrive?

Pack anyway. Scandinavian weather changes in 30 minutes. I've seen sunshine turn to hail in Bergen within an hour. Always have your rain layer accessible.

Can I just buy an umbrella there?

Umbrellas are useless in Scandinavian wind. Rain comes horizontally. You need a proper hooded rain jacket and waterproof pants if spending time outdoors.

How much should I pack for a week-long trip?

2-3 base layers, 1 insulating layer, 1 rain shell, 2 pairs of pants, 5-6 pairs of wool socks, 1 pair waterproof shoes. Laundry is available but expensive in Scandinavia.

How to Pack for Unpredictable Scandinavian Weather

Pack in layers with a waterproof outer shell, merino wool base layers, and a warm mid-layer. Scandinavian weather changes fast - you need gear that works in rain, wind, and sudden temperature drops of 15°C in one day.

Start with merino wool base layers. Pack 2-3 merino wool shirts and 2 pairs of merino underwear. Wool regulates temperature when it's hot and keeps you warm when wet. Avoid cotton completely.
Add insulating mid-layers. Bring a fleece or down jacket that compresses small. Patagonia Better Sweater or similar. This is your warmth layer for sudden temperature drops.
Get a proper waterproof shell. Invest in a Gore-Tex or similar waterproof jacket with taped seams. Must have a hood. Rain in Scandinavia isn't gentle - it's sideways and persistent.
Pack waterproof footwear. Waterproof hiking boots or shoes with good grip. Wet cobblestones in Bergen or Stockholm are slippery. Bring wool socks - 4 pairs minimum.
Include versatile pants. Pack quick-dry hiking pants and one pair of jeans. Add rain pants if hiking. Scandinavia has great outdoors but the weather won't wait for you.
Add accessories for wind and rain. Wool hat, waterproof gloves, and a neck gaiter. Wind is constant, especially on ferries between islands or walking in cities.

Do I really need expensive gear for just a city trip?: Yes. Copenhagen, Stockholm, and Oslo get sudden downpours and wind. Cheap rain gear fails when you need it most. You'll be miserable in cotton when it's 8°C and raining.
What if the weather is nice when I arrive?: Pack anyway. Scandinavian weather changes in 30 minutes. I've seen sunshine turn to hail in Bergen within an hour. Always have your rain layer accessible.
Can I just buy an umbrella there?: Umbrellas are useless in Scandinavian wind. Rain comes horizontally. You need a proper hooded rain jacket and waterproof pants if spending time outdoors.
How much should I pack for a week-long trip?: 2-3 base layers, 1 insulating layer, 1 rain shell, 2 pairs of pants, 5-6 pairs of wool socks, 1 pair waterproof shoes. Laundry is available but expensive in Scandinavia.