I have three sets of data,city, name, zip code and soil temperature on a spreadsheet. I want the soil temperature number plotted on a map with the cities name (but not within balloons).
It is basically on an New City metro map, including New Jersey, New York, Long island, Connecticut and eastern Pennsylvania. Streets and highways are not necessary but topography would be a plus.
I have been doing this by by hand for many years, but now I would like it plotted automatically. I also draw isotherms every 5 or 10 degrees, but I wonder if that can be done as well?
What free or open source program would be able to handle this task?