Spring — March to May
Spring in Reykjavik is a slow, uneven thaw. March is still properly cold (0–5°C) with a real chance of snow, sleet, and sharp wind off the bay. By May, temperatures climb to a more comfortable 7–12°C, though a warm afternoon can still turn to hail within the hour — the Icelandic saying that if you don't like the weather, wait five minutes, is not an exaggeration.
The daylight shift is dramatic: Reykjavik goes from around 11 hours of daylight in early March to nearly 18 hours by the end of May. This is one of the most underrated times to visit — the northern lights are still occasionally visible in March on clear, dark nights before the sky brightens for summer, and the crowds and prices haven't yet reached peak season.
Key events: the Reykjavik Arts Festival runs from mid-May into June, bringing international and Icelandic visual art, music, and performance across the city's venues and public spaces. Easter is widely observed with a public holiday period and quieter streets.
What to pack: a proper waterproof, windproof outer shell (a light jacket alone won't cut it), warm layers underneath, a hat and gloves for March and April, and sturdy waterproof shoes. Sunglasses for the increasingly long, bright days by May.
Summer — June to August
Summer is Reykjavik's mildest and most accessible season, though "mild" is relative — average highs sit around 12–15°C, with warm spells occasionally reaching 18–20°C and cooler, windier days common even in July. Rain is frequent but rarely heavy; a passing shower is more typical than a downpour.
The defining feature of summer is the midnight sun. Around the summer solstice on June 21, Reykjavik sees close to 24 hours of daylight — the sun dips toward the horizon but never fully sets. This disorients most first-time visitors: pack a sleep mask, because the city genuinely doesn't get properly dark. It also means you can reasonably do a Golden Circle drive at 9pm if you want to.
All Ring Road routes and highland F-roads (weather permitting) are open, making this the only season the full interior highlands, including Landmannalaugar, are accessible without specialist winter vehicles. Whale-watching sighting rates from Reykjavik's Old Harbour peak in this period.
Key events: Secret Solstice (June) is a music festival built around the midnight sun. Reykjavik Pride runs in August with a large parade through downtown. Þjóðhátíð and various town festivals (Verslunarmannahelgi, the August bank holiday weekend) see much of the city empty out to the Westman Islands and countryside.
What to pack: layers regardless of the season — a base layer, a light insulating layer, and a waterproof windbreaker on top. A warm layer for evenings even in July. A sleep mask or blackout curtains request for accommodation.
Autumn — September to November
Autumn is short and dramatic. September holds onto some summer mildness (8–13°C) with the daylight visibly shortening; by November, temperatures have dropped to 1–5°C and storms become more frequent and more powerful — Icelandic autumn gales are a genuine feature of the season, not a rarity.
This is prime northern lights season. As the nights lengthen and darken from late August onward, the aurora becomes visible on clear nights with increasing frequency through September, October, and November. Combined with still-reasonable temperatures and thinner crowds than summer, September and early October are widely considered one of the best windows to visit — good weather for hiking and driving, real darkness for aurora hunting.
Daylight drops fast: from around 13 hours in early September to under 8 hours by late November. Road conditions on mountain routes and the highlands begin to close as the month progresses; the Ring Road stays open but requires more caution.
Key events: Iceland Airwaves, held in November, is an internationally respected music festival using venues across downtown Reykjavik — a genuine draw in its own right and worth building a trip around if timing allows. Reykjavik International Film Festival (RIFF) runs in late September/early October.
What to pack: a heavier waterproof coat, warm layers, waterproof boots, gloves and a hat from October onward. A headtorch is useful as darkness comes early. Binoculars or a camera with a wide, fast lens if you're serious about the aurora.
Winter — December to February
Winter in Reykjavik is cold but not extreme by northern standards — the Gulf Stream keeps average temperatures around 0 to -3°C, milder than Reykjavik's latitude would suggest, though wind chill and storms make it feel considerably harsher. Snow falls regularly but often melts and refreezes rather than accumulating deeply in the city itself.
The defining feature is darkness. Around the winter solstice on December 21, Reykjavik gets only about 4–5 hours of weak daylight, with a low, grazing sun that never rises far above the horizon even at midday. This is disorienting for visitors used to standard day-night cycles, but it also means the northern lights season is at its peak — long dark hours from mid-afternoon to late morning give maximum opportunity for clear-sky aurora viewing. Check the forecast at vedur.is (rated 0–9) and get outside the city's light pollution when the rating and cloud cover align.
This is also the best season for the Blue Lagoon and Reykjavik's geothermal pools — soaking in 38–40°C water while snow falls or the aurora moves overhead is one of the country's defining experiences. Prices and crowds drop noticeably outside the Christmas and New Year peak.
Key events: Þorrablót, a midwinter feast held January into February, celebrates traditional preserved Icelandic foods, including some genuinely challenging delicacies like fermented shark (hákarl) and sheep's head (svið). New Year's Eve in Reykjavik is famous for a citywide, largely unregulated fireworks display — Icelanders buy and set off their own fireworks in extraordinary volume, and the sky over the city on December 31 is unlike anywhere else in Europe.
What to pack: a heavy insulated winter coat, thermal base layers, waterproof and insulated boots with good grip (pavements ice over), a warm hat, gloves, and a scarf. Studded or grippy footwear is genuinely useful, not excessive. Pack a swimsuit for the pools even in the depths of winter.