The calculated total precipitation in Iceland for 2015 was 174,485 million m3 which amounts to 1,917 mm of total precipitation on the average within Iceland. Evaporation amounted to 18,256 million m3, which means that water resources in the form of freshwater and glaciers was 175,902 million m3. The average precipitation of 1,917 mm is among the highest in Europe.
| Water resources | ||||||
| 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | |
| Million m3 | ||||||
| Total precipitation | 124,610 | 167,857 | 148,798 | 153,177 | 171,465 | 174,485 |
| Rain | 66,238 | 75,892 | 62,007 | 70,730 | 82,708 | 75,934 |
| Snow | 38,626 | 56,782 | 55,797 | 53,932 | 55,182 | 60,262 |
| Evaporation | 14,727 | 13,431 | 13,669 | 13,339 | 14,783 | 12,396 |
| Sublimation | 1,450 | 1,629 | 1,787 | 1,666 | 1,290 | 1,886 |
| Average in mm LWQ | ||||||
| Total precipitation | 1,369 | 1,844 | 1,635 | 1,683 | 1,884 | 1,917 |
| Rain | 728 | 834 | 681 | 777 | 909 | 834 |
| Snow | 424 | 624 | 613 | 593 | 606 | 662 |
| Evaporation | 162 | 148 | 150 | 147 | 162 | 136 |
| Sublimation | 16 | 18 | 20 | 18 | 14 | 21 |
Water usage in 2015 was 280 million m3 but was 275 million m3 in 2014, of which 92.8% was groundwater and 6.8% surface water. The water use for industrial companies was 198 million m3 in 2015, 71% of total usage, mostly due to fish farming and geothermal energy production. Some 77 million m3 were used in urban areas.
| Water use | ||||||
| 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | |
| Million m3 | ||||||
| Total usage | 266 | 297 | 294 | 291 | 275 | 280 |
| Corporations | 177 | 203 | 199 | 205 | 199 | 198 |
| Urban areas | 82 | 87 | 88 | 83 | 72 | 77 |
| Other use | 7 | 7 | 7 | 3 | 4 | 5 |
The Icelandic Met Office collects data on water use from all public water districts as well as from smaller water use for industrial companies gents and privately owned water abstraction wells. Water resources were simulated by the Met Office with a Harmonie simulation to calculate precipitation and evaporation for the whole country.