Observed Data Sources

These are just some of the different sources of observed climate information. An evaluation of many other observational datasets is available in the NCAR/UCAR Climate Data Guide.


Provides gridded daily rainfall and air temperature data. This dataset was created from station data and interpolated onto a regular grid. The website has a map of the stations used.

The station network in this dataset has high density and high quality for most regions; however, there are changes to the station network with time and season. The data is not homogenized, so observed time series of temperature data can be affected by changes in gauges, the location of the stations and many other factors—this might cause spurious trends. Regions, such as India, Indonesia, and Papua New Guinea lack data.

Southeast Asian Climate Assessment & Data (SACA&D) project web portal

Provides a selection of daily data and a range of climate indices computed for stations in South East Asia.

Although this website provides a good selection of extreme indices for the region, the density of the stations is quite low.  Note that only limited data is available as the data is not publicly available. You may need to talk to the contact person listed in the portal if you need to access data that is not available.

Advancing Reanalysis website

Contains links to some widely used reanalysis datasets, including the ECMWF-ERA from the European Centre for Medium Range Weather Forecasting and the NCEP/NCAR Reanalysis. These datasets provide state-of-the-art gridded data used to initialize models to both evaluate model performance and assess observed trends.

These datasets provide a range of atmospheric variables. However, some care must be taken as some variables are model generated and not directly forced by observations. For example, most reanalysis datasets provide rainfall that is generated by the underlying models and should not be relied upon as accurate depictions of the real rainfall. The observed gridded datasets are derived directly from observed rainfall and are more reliable guides to rainfall.

Tropical Rainfall Measuring Mission (TRMM)

Provides a 17-year dataset of global tropical rainfall at a spatial resolution of 0.25° × 0.25° grid size. The data derived from the space using remote sensing satellite technique.

Climatic Research Unit (CRU)

Provides several global climatology dataset including temperature, precipitation and pressure at a coarse spatial resolution of 5°× 5° grid. Recently, the CRU also provides high-resolution gridded datasets and derived products.

Terrestrial Hydrology Research Group, Princeton University

Provides a high-resolution global 50-year dataset of meteorological variables required to drive models of land surface hydrology. The data was constructed by combining some global observation-based datasets along with the NCEP/NCAR reanalysis data mentioned above.