The datasheet lists two temperature ranges, operating and storage, plus 95% non-condensing humidity. How do we read them correctly?

The two ranges apply to different situations, and mixing them up leads to the wrong machine. Operating temperature: the machine is running and still guaranteed to work correctly. This is the figure to select by. For example, 0…50 °C is a standard range, while -20…60 °C or -40…70 °C is wide-temp. Storage temperature: the machine is switched off, stored or shipped, without damage. This range is always wider, for example -40…85 °C, but it does not mean the machine can run there. 95% non-condensing humidity: it tolerates air up to 95% humidity as long as water does not condense into droplets on the boards. Where temperature changes quickly (cold stores, outdoor cabinets that are cold at night and hot by day), moisture can still condense below 95%, so extra anti-condensation measures are needed. Always read the footnotes: the temperature range usually applies only to one specific CPU configuration and storage type.