Dettifoss: water levels by month
Short answer: Dettifoss carries the most water in July (about 324 m³/s on the Jökulsá á Fjöllum) and the least in March (about 118 m³/s, 2.7 times less).
Glacial melt makes summer flow the strongest; the access roads can close in winter.
River flow through the year
| Month | Flow (share of peak) | Average m³/s | Level |
|---|---|---|---|
| January | 38% | 122 | Low water |
| February | 37% | 119 | Low water |
| March | 36% | 118 | Low water |
| April | 48% | 155 | Medium |
| May | 69% | 225 | Medium |
| June | 96% | 312 | High water |
| July | 100% | 324 | High water |
| August | 80% | 260 | High water |
| September | 60% | 196 | Medium |
| October | 57% | 184 | Medium |
| November | 45% | 147 | Medium |
| December | 39% | 125 | Low water |
Tours
Questions
When is the best time to see Dettifoss?
Dettifoss carries the most water in July (about 324 m³/s on the Jökulsá á Fjöllum) and the least in March (about 118 m³/s, 2.7 times less). Glacial melt makes summer flow the strongest; the access roads can close in winter.
When is Dettifoss at its lowest?
March has the lowest average flow (36% of the July peak).
Average daily river discharge 2005-2024 from the GloFAS v4 hydrological reanalysis (Copernicus Emergency Management Service) via Open-Meteo, for the model river cell nearest the falls. Dams and diversions upstream can change real flow on the day.