How To Compare Two Data Sets From The Same Time And Proximate Location

Hi there, my first post not sure if this is the sub for it,

So I am working on a weather datasets (taken from stats can:https://climate.weather.gc.ca/index_e.html), The dataset I am working with has some missing values that I wish to fill using another dataset from a similar location. For this I found two other datasets from similar location, but both report slightly different numbers (as expected).

I wanna figure out if these differences are significant enough for me to not choose these datasets. How do I go about this? Do I use t test individually on each column? or ANOVA?