HCX-IR High-Resolution (1/8°) Observational and CMIP6 Downscaled Climate Dataset for Iran

This dataset provides a high-resolution (1/8) gridded daily climate data product with nationwide coverage of Iran, spanning both historical observations (1980–2012) and CMIP6-based historical and future projections (1980–2100) under SSP245 and SSP585 emission scenarios. It includes three components: (1) HCX-IR-Obs, a gridded observational dataset generated from synoptic station records of the Iran Meteorological Organization using the SYMAP interpolation method; (2) HCX-IR-MBC, a CMIP6 multi-model ensemble downscaled using the Multivariate Bias Correction (MBC) technique; and (3) HCX-IR-BCCAQ, a CMIP6 product downscaled using the Bias Correction Constructed Analogs with Quantile Mapping (BCCAQ V2) method. All components are provided on a uniform 1/8° spatial grid covering Iran and contain daily values of precipitation (pr), minimum temperature (tasmin), and maximum temperature (tasmax). The downscaled simulations incorporate historical and future projections from eight CMIP6 global climate models (CanESM5, CNRM-CM6-1, GFDL-ESM4, MIROC-ES2L, MPI-ESM1-2-HR, MPI-ESM1-2-LR, NorESM2-LM, and IPSL-CM6A-LR), selected based on their representation of climate variability and extremes, as described in Najafi et al. (2025) (https://doi.org/10.1002/joc.8740). All model outputs are bias-corrected against the HCX-IR-Obs reference dataset. The dataset supports climate change assessment, regional climate impact studies, and hydrological and environmental modeling across diverse climatic regions of Iran, including arid, semi-arid, and mountainous areas. Quality assurance included comparison with global reference datasets (CRU, NCEP, and 20CR), and evaluation of spatial patterns, seasonal climatology, and climate extremes indices.