Click on a day for an hourly weather forecast
The temperatures in Grindavik in September are quite cold with temperatures between 8°C and 10°C, warm clothes are a must.
You can expect rain for roughly half of the month of September in Grindavik. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Grindavik in September 2025.
If you’re planning to visit Grindavik in the near future, we highly recommend that you review the 14 day weather forecast for Grindavik before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 4° / 1° | 14 | 6 | 11 | 203 mm | Awful | Grindavik in January |
| February | 4° / 1° | 12 | 7 | 9 | 178 mm | Awful | Grindavik in February |
| March | 4° / 2° | 13 | 7 | 11 | 183 mm | Awful | Grindavik in March |
| April | 5° / 3° | 13 | 12 | 6 | 146 mm | Awful | Grindavik in April |
| May | 8° / 5° | 11 | 19 | 1 | 125 mm | Bad | Grindavik in May |
| June | 10° / 8° | 7 | 23 | 0 | 88 mm | Bad | Grindavik in June |
| July | 12° / 10° | 7 | 24 | 0 | 102 mm | Bad | Grindavik in July |
| August | 12° / 10° | 7 | 24 | 0 | 124 mm | Bad | Grindavik in August |
| September | 10° / 8° | 13 | 17 | 0 | 204 mm | Bad | Grindavik in September |
| October | 8° / 5° | 12 | 17 | 1 | 184 mm | Bad | Grindavik in October |
| November | 6° / 3° | 13 | 11 | 6 | 160 mm | Awful | Grindavik in November |
| December | 4° / 2° | 11 | 11 | 9 | 156 mm | Awful | Grindavik in December |