The thing to do for any burn, immediately, is to grab a pack of frozen vegetables or an ice pack or ice in a baggie and apply it for 15 minutes to the burned area. This will reduce the pain, limit the spread of the burn, and be of great relief.
I would say that in the south (Algarve) the weather should be around 25Â°C, and still probably beach weather. In Lisbon it would probably be colder, probably around 20Â°C, so probably not the right weather to go to the beach. More info here: September Weather Averages for Algarve, Portugal, and September Weather Averages for Lisbon, Portugal. Views Â· View Upvotes.
When to travel to Portugal: weather and seasons. 1  Weather in Portugal varies considerably from one region to another. 2  Personally, I think the best time to travel to Portugal is during spring and autumn, when days are pleasantly sunny and warm but tourist areas are relatively quiet. 3  Summers are dry and clear, with warm sunshine extending.