Hello. I just goofed and posted this question on the "France" site. So I'll just repost it here - where it belongs. My grandchildren & I will be in Lucerne in July - with side trips to Mt. Pilatus where we'll take the cable car and alpine slide, as well as a short boat ride on Lake Lucerne. Even though it'll be in July I'm wondering if we should pack some warmer clothing for this visit (long pants, jackets, etc.), or would shorts suffice? Thanks for any help you can give me. Linda
When in the mountains dress in layers. As for Lucerne - I would definitely want a hotel room with Air Condition.
I posted an answer to your question in the Europe section.
Mean climate statistical data for Luzern: https://www.yr.no/place/Switzerland/Lucerne/Lucerne/statistics.html
July mean high = 19.9C
July mean low = 9.7C
Higher places are colder than lower places all thing being equal. Without getting into the physics temperature drops with incease in elevation and the magnitue of the lower temperature depends on the amount of moisture in the air. If you want to be a science nerd, look up "lapse rate": https://en.wikipedia.org/wiki/Lapse_rate
While the dry adiabatic lapse rate is a constant 9.8 °C/km (5.38 °F
per 1,000 ft, 3 °C/1,000 ft), the moist adiabatic lapse rate varies
strongly with temperature. A typical value is around 5 °C/km, (9
°F/km, 2.7 °F/1,000 ft, 1.5 °C/1,000 ft).
Luzern is about 420 masl and the top of Pilatus is at 2128 masl, a 1708 meter differance. The dry air temerature difference between Luzern and to top of Pilatus could be about 9.8 x 1.7 = 16.6C colder. The moist air difference would be lower, about 5 x 1.7 = 8.5C colder.
And then there is wind chill. Layer with a moisture proof or water proof outer shell if you are sightseeing, something more bomb proof if you are doing more extreme travel.