Daylight / 01
From 21 hours to 4
Around the summer solstice (~21 June), Reykjavík gets roughly 21 hours of daylight and true darkness disappears for weeks — driving time is essentially unlimited. Near the winter solstice (~21 December), usable daylight drops to about 4–5 hours, with sunrise near 11:20 and sunset around 15:30. By late January that's back up to roughly 9 hours, and by late March to nearly 16.
Summer (Jun–Aug) / 02
Peak season, peak crowds, easiest roads
All Route 1 sections are open and most F-roads become accessible from June. The trade-off is the accommodation and car-park crowding described throughout this site — book lodging 3–6 months ahead for July.
Shoulder (Apr–May, Sep–Oct) / 03
Fewer crowds, shrinking services
Daylight is still generous but shrinking fast, and some seasonal services (certain F-roads, some tour operators) start closing. Expect our route-dial's shoulder-season time multiplier (roughly +15%) to reflect real slower driving, not just caution.
Winter (Nov–Mar) / 04
Short days, real closures
Sections like Dettifoss's west road (862) lose winter service roughly January to early April, and the east road (864) stays closed until late May. Wind advisories matter more, and daylight can force you to stop driving by mid-afternoon. Always check road.is, Veður.is, and SafeTravel same-day, not the night before.