In terms of precipitation, rainfall in Arlanda ranges from 1.0 - 2.8 inches per month. July is typically the wettest month, when rainfall can reach 2.8 in. March is typically the driest time to visit Arlanda when rainfall is around 1.0 in.
If weather is an important factor for your trip to Arlanda, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of February, when temperatures are typically at their lowest (around 26.6 F).