We went end of June 2017 high mid 60. Rainy. Lovely. Wear layers and raincoat.
It's in 60-70s...perfect weather.
I was there in July and the highs were in the high 50's to the mid to high 60's. My suggestion is to layer your clothes and take a light back pack to use as you remove layers. I used undershirt, turtle neck shirt or other long sleeve or short sleeve tee shirt with a best and light jacket and a light weight breathable rain jacket. Add a scarf with cap and gloves for colder days.
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