|United States Historical Climatology Network|
(Aka USHCN) A network that produces a dataset of daily and monthly records of basic meteorological variables from 1218 observing stations across the 48 contiguous United States.
It was put together under the leadership of Tom Karl to get data that was free of urban bias contamination. For more detailed information, click here.
1. It is one of the datasets that NASA's GISTEMP uses to calculate monthly global surface temperatures.