average july weather in oslo norway
1 The average temperature in Oslo in July is very mild at 16.4 Â°C (61.52 Â°F). 2  Afternoons can be really warm with average high temperatures reaching 22 Â°C (71.6 Â°F).  Overnight temperatures are generally mild with an average low of 13 Â°C (55.4 Â°F).