September marks Iceland's transition into autumn, offering some of the most pleasant weather conditions of the year. Average temperatures in Reykjavík range from 6°C to 11°C, making it considerably mo...
Weather & Climate
September marks Iceland's transition into autumn, offering some of the most pleasant weather conditions of the year. Average temperatures in Reykjavík range from 6°C to 11°C, making it considerably more comfortable than the summer months whilst still avoiding winter's harsh conditions. The southern coast, including areas around Vík and Höfn, tends to be slightly warmer, with temperatures reaching up to 12°C on favourable days.
Rainfall increases noticeably in September, with Reykjavík receiving approximately 67mm throughout the month—nearly double July's precipitation. The weather becomes increasingly unpredictable, with sudden showers followed by brilliant sunshine, embodying the Icelandic saying "if you don't like the weather, wait five minutes." Snowfall is rare but not impossible, particularly in the highlands above 500 metres elevation. The Westman Islands and Reykjanes Peninsula typically remain snow-free, whilst areas like Landmannalaugar and the Kjölur route may experience their first dustings.
Wind patterns shift in September, with stronger southwesterly winds becoming more frequent. Coastal areas, particularly around the Westfjords and along the south coast near Reynisfjara, can experience gusts exceeding 15 m/s. These conditions, whilst challenging for outdoor activities, create spectacular wave formations and dramatic coastal photography opportunities.
Daylight hours decrease rapidly throughout September, dropping from approximately 16 hours at the month's beginning to just over 13 hours by its end. This dramatic change signals the approaching winter and marks the return of meaningful darkness—crucial for aurora viewing.
Daylight & Light Conditions
September's most significant change involves the rapid decrease in daylight hours. On 1st September, sunrise occurs around 06:30 with sunset at approximately 20:30 in Reykjavík. By month's end, sunrise shifts to 07:45 and sunset to 19:15, creating a noticeable difference in daily rhythm.
The midnight sun phenomenon has completely ended, with astronomical darkness returning for the first time since April. This transition proves particularly striking for visitors who experienced Iceland's endless summer days, as the contrast becomes immediately apparent.
Aurora visibility becomes possible again from mid-September onwards, though optimal conditions typically begin around the 20th when astronomical darkness sufficiently deepens. The aurora season's return generates considerable excitement, as September often provides the first opportunity to witness the Northern Lights after the summer hiatus.
Photography enthusiasts will find September's golden hour conditions exceptional, with lower sun angles creating warm, dramatic lighting throughout more extended periods. The combination of autumn colours—particularly vibrant around Þórsmörk and the Highlands—with improved lighting conditions makes this month outstanding for landscape photography.
What to Do in September
**1. Landmannalaugar and Laugavegur Trek**
September offers the final opportunity to access Landmannalaugar via the mountain roads before winter closures. The famous hiking area showcases spectacular autumn colours, with the rhyolite mountains providing a stunning backdrop to golden grasses and red berries. The Laugavegur trek remains accessible, though hikers should prepare for potential snow at higher elevations and rapidly changing weather conditions.
**2. Þórsmörk Valley**
The "Valley of Thor" displays some of Iceland's most brilliant autumn foliage in September. Accessible via the F249 road, Þórsmörk offers numerous hiking trails including the popular Valahnúkur summit trail. The birch forests reach peak autumn colours, creating a golden canopy that contrasts beautifully with the surrounding glacial peaks of Eyjafjallajökull and Mýrdalsjökull.
**3. Westfjords Circuit**
September provides excellent conditions for exploring the remote Westfjords before winter isolation sets in. The dramatic cliffs of Látrabjarg host thousands of seabirds, whilst Dynjandi waterfall flows at substantial volume from summer glacial melt. The challenging mountain passes remain accessible, though conditions can deteriorate rapidly.
**4. Snæfellsnes Peninsula**
Often called "Iceland in Miniature," the Snæfellsnes Peninsula offers diverse landscapes within a manageable driving circuit. Kirkjufell mountain provides excellent aurora photography opportunities once darkness returns, whilst the fishing villages of Arnarstapi and Hellnar showcase dramatic coastal geology. Snæfellsjökull glacier creates an imposing backdrop throughout the peninsula.
**5. South Coast Waterfalls**
September's increased rainfall enhances waterfall volumes along the famous south coast route. Seljalandsfoss and Skógafoss display impressive power, whilst the lesser-known Kvernufoss offers a more intimate experience. Gljúfrabúi, hidden behind Seljalandsfoss, becomes particularly atmospheric in autumn conditions.
**6. Jökulsárlón and Diamond Beach**
The glacier lagoon experiences optimal visiting conditions in September, with comfortable temperatures for boat tours and excellent photography lighting. Icebergs calving from Breiðamerkurjökull glacier create ever-changing compositions, whilst Diamond Beach showcases ice fragments against black volcanic sand under increasingly dramatic skies.
**7. Reykjanes Peninsula and Blue Lagoon**
The geothermal areas of Reykjanes Peninsula, including the recently active Fagradalsfjall volcanic area, remain accessible throughout September. The Blue Lagoon provides a perfect contrast to cooler autumn temperatures, whilst the raw landscape around Grindavík offers insights into Iceland's volcanic nature.
**8. Highland F-Roads Final Access**
September represents the last reliable month for highland access via F-roads. The Kjölur route (F35) connecting north and south Iceland typically remains open, offering views of Langjökull glacier and access to Gullfoss waterfall from an alternative approach. However, conditions can change rapidly.
**9. Puffin Watching at Westman Islands**
Early September provides final opportunities to observe puffins before their winter migration. Heimaey island in the Westman Islands hosts substantial colonies, accessible via ferry from Landeyjahöfn. The dramatic volcanic landscapes, including areas affected by the 1973 eruption, add geological interest to wildlife observation.
**10. Northern Iceland and Lake Mývatn**
The Lake Mývatn area showcases unique volcanic formations under increasingly dramatic autumn lighting. Dimmuborgir lava fields, Námafjall geothermal area, and the powerful Dettifoss waterfall all benefit from September's comfortable temperatures and extended golden hour conditions.
F-Road & Highland Access
September marks the beginning of highland road closures, though many routes remain accessible early in the month. The Icelandic Road and Coastal Administration (Vegagerðin) closely monitors conditions and issues closure notices based on weather forecasts and road conditions.
The F35 Kjölur route typically remains open throughout September, connecting the south coast to northern Iceland via the interior. This high-altitude route passes between Langjökull and Hofsjökull glaciers, offering spectacular highland scenery. However, snow and ice can appear suddenly, making 4WD vehicles essential.
Landmannalaugar access via F208 and F224 usually continues until late September or early October, depending on weather conditions. These routes require river crossings and traverse challenging terrain, making them suitable only for experienced drivers with appropriate vehicles.
The F26 Sprengisandur route, Iceland's longest highland track, typically closes earlier than other F-roads due to its extreme elevation and exposure. By mid-September, this route often becomes impassable due to snow and ice formation.
The F910 Askja route and F88 Kverkfjöll approach generally close by early September, as these northern highland areas receive snow earlier than southern routes. The challenging terrain and river crossings become increasingly dangerous as temperatures drop.
Local F-roads accessing specific attractions like Þórsmörk (F249) and various hot springs may remain open longer, though conditions vary significantly based on elevation and exposure. Always check current road conditions at road.is before attempting any F-road travel.
Aurora Forecast
September marks the return of aurora season after the summer hiatus, though optimal conditions develop gradually throughout the month. Aurora activity depends on solar activity, clear skies, and sufficient darkness—all factors that improve as September progresses.
The first meaningful aurora opportunities typically occur around 15th-20th September, when astronomical darkness deepens sufficiently. Early September still experiences too much ambient light from extended twilight periods, limiting aurora visibility even during active geomagnetic conditions.
Prime aurora viewing locations include the Reykjanes Peninsula, particularly around Grindavík and the Blue Lagoon area, where light pollution remains minimal. The south coast between Selfoss and Vík offers excellent viewing opportunities, with iconic foregrounds like Seljalandsfoss and Kirkjufell providing photographic interest.
Northern Iceland, including areas around Lake Mývatn and the Tröllaskagi peninsula, typically experiences darker skies earlier in the season. However, cloud cover can be more persistent in these regions during autumn months.
Realistic expectations for September aurora viewing suggest approximately 8-12 clear nights with sufficient darkness for observation, depending on weather conditions and solar activity. The aurora season's return often generates excitement, but patience remains essential as cloud cover frequently obscures viewing opportunities.
The best aurora viewing times in September occur between 22:00 and 02:00, though activity can begin earlier as the month progresses and darkness increases. Aurora forecasting websites and apps provide valuable guidance, though local weather conditions ultimately determine viewing success.
What to Pack
September's variable conditions require versatile clothing suitable for rapid weather changes. A layering system proves most effective, allowing adjustment to temperature fluctuations and activity levels throughout the day.
**Base Layers**: Merino wool or synthetic moisture-wicking materials provide warmth whilst managing perspiration during active pursuits. Pack at least two sets to allow for washing and drying.
**Insulating Layers**: A warm fleece or down jacket handles temperature drops, particularly during evening aurora watching. Down provides superior warmth-to-weight ratio but loses insulating properties when wet, making synthetic alternatives preferable for active use.
**Outer Layers**: A waterproof, breathable shell jacket and trousers prove essential for Iceland's unpredictable precipitation. Look for garments with sealed seams and adjustable hoods to handle driving rain and wind.
**Footwear**: Waterproof hiking boots with good ankle support handle Iceland's varied terrain and frequent wet conditions. Consider bringing gaiters for additional water protection during river crossings and muddy trails. Comfortable walking shoes for urban exploration and indoor venues provide relief from heavy boots.
**Accessories**: Waterproof gloves, warm hat, and neck gaiter become increasingly important as temperatures drop. A headlamp proves invaluable for early morning starts and aurora watching, whilst sunglasses remain necessary during bright conditions.
**Technical Gear**: A waterproof camera bag protects equipment during sudden weather changes. Extra batteries perform poorly in cold conditions, so keep spares warm. A tripod enables aurora photography and long exposure landscape shots.
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