iceland average monthly temperatures
- Reykjavik: Annual Weather Averages. July is the hottest month in Reykjavik with an average temperature of 11Â°C (52Â°F) and the coldest is January at 0Â°C (32Â°F) with the most daily sunshine hours at 12 in March.The wettest month is January with an average of 50mm of rain.eykjavik: Annual Weather Averages. July is the hottest month in Reykjavik with an average temperature of 11Â°C (52Â°F) and the coldest is January at 0Â°C (32Â°F) with the most daily sunshine hours at 12 in March.