The Global Climate at a Glance (GCAG) web application can be
used to retrieve monthly and annual global temperature anomaly
maps that date back to 1880. Users can also create timeseries
for locations around the globe by selecting a point on the map.
The interactive interface allows users to adjust the vertical
and horizontal axes of the timeseries plots to view selected
range of months or years of data or to view the entire period of
record. The maps are created using land surface temperature
anomalies from the Global Historical Climatology Network (GHCN)
data and sea surface temperature anomalies from the
International Comprehensive Ocean-Atmosphere Data Set (ICOADS).
These two datasets are blended into a single product to produce
the combined global land and ocean temperature anomalies. The
temperature anomalies are calculated with respect to the
1971-2000 base period and are averaged over 5 degree by 5 degree
grid boxes. These gridded temperature anomalies are mapped by
GCAG. Additional information on the