[zeotroph]

> clear day

That is not enough though. Since the temperature drops during any eclipse the air can suddenly hold a lot less water and you have fog ruining your view. So a place with lower humidity is the second thing to consider after the cloud cover itself.

[repiret]

Will less than three minutes of darkness actually cool the air very much?

[zeotroph]

"3/4 or 1/2 the maximum day-night temperature difference" says eclipse2017.nasa.gov[0], space.com has more details on that[1]. If this drop means the air cools below its current dew point you get fog. Seen and felt it twice with partial eclipses (both of which just happened to be where I was, so no loss).

[0] https://eclipse2017.nasa.gov/typically-how-big-temperature-d... [1] https://www.space.com/37201-solar-eclipse-temperature-drop.h...