If you’re hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Oban: The hottest months are usually July and August, with an average temperature of 13°C, while the coldest months are January and February, with an average of 5°C. The rainiest months in Oban are October, December, November and January, with each month seeing an average of 266 mm of rainfall.