Dettifoss rainbow: when and where to stand
Short answer: 6 Nov 2026: Best rainbow from East bank viewpoint, 10:00–12:45 (strongest around 10:00), if the sun is out.
Europe's most powerful waterfall throws a column of spray out of the Jökulsárgljúfur canyon. You can view it from either bank, and the two sides get their rainbows at opposite ends of the day.
Fri 6 November 2026 · sunrise 09:19, sunset 16:21
East bank: rainbow 10:00–12:45
Best rainbow from East bank viewpoint, 10:00–12:45 (strongest around 10:00), if the sun is out. Medium water.
| East bank viewpoint looking west across the canyon | A big, bright arc | 10:00–12:45 Best 10:00, low, down in the spray below you |
|---|---|---|
| West bank viewpoint looking east across the canyon | A big, bright arc | 13:00–15:45 Best 14:00, across the spray at eye level |
Hour by hour
| Time | East bank | West bank |
|---|---|---|
| 09:00 | ||
| 09:30 | ||
| 10:00 | ||
| 10:30 | ||
| 11:00 | ||
| 11:30 | ||
| 12:00 | ||
| 12:30 | ||
| 13:00 | ||
| 13:30 | ||
| 14:00 | ||
| 14:30 | ||
| 15:00 | ||
| 15:30 | ||
| 16:00 | ||
| 16:30 |
Plan it
The east bank (road 864) is gravel and often closed until June; the west bank (road 862) is paved. Glacial melt makes July and August the most powerful. A rainbow needs direct sun on the spray: on an overcast day there is none.
Through the year
| 15th of | East bank | West bank | Water |
|---|---|---|---|
| January | 12:10–13:10 | 13:30–14:30 | Low |
| February | 09:50–13:20 | 13:30–17:00 | Low |
| March | 08:00–13:25 | 13:10–18:40 | Low |
| April | 06:00–13:30 | 12:50–20:20 | Medium |
| May | 04:20–13:25 | 12:45–21:55 | Medium |
| June | 03:10–13:30 | 12:55–23:10 | High |
| July | 03:50–13:35 | 13:00–22:40 | High |
| August | 05:20–13:35 | 12:55–21:05 | High |
| September | 07:00–13:20 | 12:55–19:10 | Medium |
| October | 08:35–12:55 | 13:00–17:15 | Medium |
| November | 10:40–12:45 | 13:05–15:05 | Medium |
| December | — | — | Low |
Dettifoss rainbows by month
Questions
What time is the rainbow at Dettifoss?
6 Nov 2026: Best rainbow from East bank viewpoint, 10:00–12:45 (strongest around 10:00), if the sun is out. The time moves through the year; pick your date above.
Which side of Dettifoss has the rainbow in the morning and which in the afternoon?
East bank viewpoint: mornings. West bank viewpoint: afternoons.
Why is there no rainbow at midday?
When the sun is higher than about 42°, the whole rainbow circle sits below the horizon. You can then only see it low down, in spray below you, if at all. In summer that rules out the middle of the day at most falls closer to the tropics.
When does Dettifoss have the most spray?
River flow is highest in June, July and August (Copernicus GloFAS, 2005–2024). More water means more spray and bigger rainbows, but also more mist hiding the falls.
How do you calculate the rainbow times?
A rainbow is a circle of about 42° around the point exactly opposite the sun. You only see the part of that circle that falls on sunlit spray, so it needs the sun behind you and lower than about 42° above the horizon. For every 5 minutes of the day we place that circle in the sky and check how much of it lands on the spray seen from each viewpoint.
Calculated from the sun's position at each viewpoint. The spray extent is an estimate for normal flow; wind pushes the mist around and can move the rainbow by a few degrees. Times are local (Atlantic/Reykjavik).