How to reduce noise in spatial data



My question is how does one smooth data which is given in terms of latitude and longitude.

If, say, temparature is given on a daily basis then we can smoothen it by using a moving average of temperature of a given number of days. But suppose the temperature was given in terms of latitude and longitude instead of time, then how does one proceed with smoothing the data. Is there any R package which makes this easy to do ?