I did not miss isolines, because there is already colour. Few remarks: 1) it is fast, it looks well. 2) I remember (poorly) there are a lot of methods how to extrapolate isolines from point measurement, which changes result (sometimes dramatically). 3) when we just drew isolines at school we should avoid spikes (as they are unphysicall). I do now know if it should be avoided also in objective analysis. Although, I see a little spike in your result.
Anyway: Good job.

I did not miss isolines, because there is already colour. Few remarks: 1) it is fast, it looks well. 2) I remember (poorly) there are a lot of methods how to extrapolate isolines from point measurement, which changes result (sometimes dramatically). 3) when we just drew isolines at school we should avoid spikes (as they are unphysicall). I do now know if it should be avoided also in objective analysis. Although, I see a little spike in your result.
Anyway: Good job.