I have a dataset of certain events that I want to analyze based off of location. At the most granular level, for each event point, I have its latitude and longitude. However, I have temperature and precipitation data available at a more macro level (i.e. temp or precipitation points for each 6 square km) that I want to include in the analysis.

How do I merge the two levels of geolocation available? i.e. how do I make a broader group id that I can assign to clusters of events so that I can merge the temp / precipitation data with the event data? Should I employ GIS?

Thanks!