Places that have never experienced an "ice day" nor a "tropical night" (climate, warmest)

[HumidSubPolar]

An ice day is a day on which the maximum temperature doesn't exceed 0 °C and a tropical night is a night on which the minimum temperature exceeds 20 °C. Probably no part of the tropics has experienced an ice day and most continental locations far north haven't experienced a tropical night. The vast majority of the mid-latitudes has experienced both. My guess is that a location that has experienced neither would have to be maritime in the mid-latitudes: Eureka, California, is the only example I could find (the coldest day was 1°C and the warmest night 17 °C). Campbell island (NZ) and Tristan Da Cunha might also be examples, but I couldn't find exact data to prove it. Come to think of it, equatorial high altitude places like La Paz, are also candidates.

[sanfel]

Originally Posted by HumidSubPolar

Come to think of it, equatorial high altitude places like La Paz, are also candidates.

La Paz is at 16°S, so there is slightly more variability than truly equatorial locations, like Bogotá and Quito. The latter two almost certainly meet those criteria.

Originally Posted by HumidSubPolar

and most continental locations far north haven't experienced a tropical night.

Also, most locations far south in southern South America (Argentina and Chile) haven't experienced a tropical night either. Places like Punta Arenas, Ushuaia, Río Gallegos, Río Grande. And they usually have a couple of ice days almost every winter.

[CRISPR]

I think very maritime climates in the Southern Ocean would fit the bill.
Tristan da Cunha- https://en.wikipedia.org/wiki/Tristan_da_Cunha#Climate
Gough Island-https://en.wikipedia.org/wiki/Gough_Island#Climate
ÃŽle Amsterdam- https://en.wikipedia.org/wiki/%C3%8Ele_Amsterdam#Climate