Iceland · Month comparison

July vs September

September ranks #1 overall vs July at #12. Aurora returns, autumn colours explode, crowds drop — the most atmospheric month in Iceland.

Iceland July — Skógafoss waterfall thundering into a vivid green summer valley at dawn

July

#12 of 12 months

Strong option

Warmest month, every road open — absolute peak for crowds and prices.

  • Warmest temperatures of the year (14°C): most comfortable conditions for hiking and outdoor activities
  • All roads and trails fully open: full Laugavegur Trail, Fimmvörðuháls, and Kjölur highland route accessible
Iceland September — aurora borealis shimmering over a calm mountain lake with the season's first northern lights reflected in the water

September

#1 of 12 months

Best match

Aurora returns, autumn colours explode, crowds drop — the most atmospheric month in Iceland.

  • Aurora borealis returns from early September as nights grow long enough — first sightings of the new season
  • Autumn colours (yellows, reds, oranges across the highlands) peak in September — uniquely photogenic landscapes
FactorJulySeptember
Weather score
8
6
Value score
1
6
Crowd score
2
7
Events score
7
7
Atmosphere
7
9
Avg high temp14°C10°C
Monthly rain52mm67mm
Daily sunshine12.8hrs8.5hrs

July trade-offs

  • Peak prices across the board: accommodation, car hire, tours, and flights all at annual maximums
  • Most popular sites — Seljalandsfoss, Skógafoss, Jökulsárlón — crowded throughout the day
  • No aurora whatsoever; midnight sun means the sky never darkens

September trade-offs

  • Temperatures drop quickly (10°C high); warm layers essential and weather windows shorter
  • Highland F-roads closing progressively through September — some interior routes blocked by late month
  • Aurora is back but not yet at winter frequency — nights still shorter than January–March
Scores compare months within Iceland. Climate data: Open Meteo ERA5 30-year normals (1991–2020). Methodology →