Climate Data


JRA-25 is a second generation reanalysis product. The model and data assimilation are from the operational system in April 2004. It was the first reanalysis to assimilate wind profiles around tropical cyclones deduced from best-track data, resulting in improved tropical cyclone analysis in a global context. In addition, low-level (stratus) cloud decks along the western subtropical coasts of continents are also better simulated, improving radiation budgets in these regions. A primary goal of JRA-25 is to provide a consistent and high-quality reanalysis dataset for climate research, monitoring, and operational forecasts, especially by improving the coverage and quality of analysis in the Asian region. Note: JRA-25 has been superseded by the JRA-55 reanalysis, a 3rd generation product.

Key Strengths:

  • Long time series of the global precipitation is the best among the other second generation reanalyses
  • Assimilate wind profiles around tropical cyclones
  • Low-level cloud along the subtropical western coast of continents is well simulated

Key Limitations:

  • Does not account for satellite biases. Can affect trend; large temperature biases in stratosphere
  • CO2 held constant for all 25 years
  • Cold bias in lower stratosphere; Dry bias over Amazon

Years of Record

1979/01 to 2004/12
temporal metadataID:



Sub-daily | Monthly

Data Time Period Extended?

no, data set not being extended


Spatial Resolution

1.125x1.125/2.5x2.5; 0.4 hPA top

Ocean or Land


Missing Data Flag

spatially complete

Data Assimilation Method

Model Resolution used to create reanlaysis

T106, 40 levels

Model Vintage (reanalysis)


Earth system components and main variables

Usage Restrictions

Research only; No redistribution
  1. Onogi, K., & others, 2007: The JRA-25 Reanalysis. J. Met. Soc. Jap., 85(3), 369-432.

Key Figures

Click the thumbnails to view larger sizes



Annual temperature range of 2-meter temperature (C) from JRA25. (Climate Data Guide; D. Shea)

Cite this page

National Center for Atmospheric Research Staff (Eds). Last modified 05 Jul 2016. "The Climate Data Guide: JRA-25." Retrieved from

Acknowledgement of any material taken from this page is appreciated. On behalf of experts who have contributed data, advice, and/or figures, please cite their work as well.