If I may add a few comments:
- The idea is awesome, I myself lived in 4 countries (and different regions) within the last 6 years, and such tool would be handy for me.
- As a frequent nomad I look at the economic and social factors rather than climate and culture to which I am flexible. Rainfall and snowfall rates give me no information on climate, however knowing that it rains in Israel only in winter time draws a different picture for me. And Google search gives quite lower numbers on Moscow average humidity 60% vs 76%. Adding Celcius (as you did with cm in rainfall) would be good. I am Euriopean and Forenheit confuse me.
- I think in cities comparison comfort score is the lead "index" but it needs to show the criterias included in this index.
- It would be cool if every city would have a short summary on climate, as it would give much more of an idea of the city comfort.
Hope this helps.