A method for temperature interpolation is provided. In an embodiment climatology records and temperature observations are received by a weather computing system over a network from an outside source. The temperature observations are subtracted from the climatology records to create anomalies. The anomalies are extrapolated across a map using various modeling methods and stored in the volatile memory of weather computing system. When the weather computing system receives a request for a temperature at a specific location, the weather computing system retrieves the anomaly field from the volatile memory and applies it to the climatology records at the requested location to determine the temperature for that location.