Wetlands have vital roles for biodiversity and ecosystem services to human societies, but wetland area is declining around the globe, including in Iran, which spans several climate zones (arid, semi-arid, dry, humid, humid) and has experienced large hydrological changes in recent decades. To facilitate the examination of wetland-climate change interactions, this study develops a new dataset for 136 natural wetland sites across Iran and its climate zones. The dataset includes physical characteristics, and societal sector uses of the wetlands, along with the wetland and climate changes that have occurred at each wetland site over 1992-2020. Application of the dataset to understanding the possible climate change role in driving wetland decline reveals that the area of Iranian wetlands has decreased by -36% over the country, by -61% and -50% in arid and semi-arid zones, respectively. At the scale of the whole country, the wetland decline is overall consistent with the climate change directions of temperature (warming) and precipitation (mainly decreasing). This dataset is a useful tool for further research to resolve main climatic and non-climatic driver-impact relationships for integrated catchment-wetland systems. The database is provided in an Excel (xsls) file, comprising and organized 30cloumns as follows: Title Description Title Description ID Wetland ID number (as shown in Fig.1) Perimeter Maximum perimeter length of wetland (km) Name (in Persian) Name of wetland in Persian Depth Maximum possible depth of wetland (m) Name Name of wetland in English Regime Permanent, seasonal Ramsar 1=If wetland is on Ramsar Convention list, 0=If wetland is not on Ramsar Convention list. ΔAloc Area change (km2) X Longitude of wetland center Type (size) Classification of wetland size based on area: small (<250 km2); medium (250-800 km2); large (>800 km2) Y Latitude of wetland center Saline /Fresh 1= Saline water 0=Freshwater T Long-term temperature average for wetland site (°C) Wetland water Sector usage Tourism 1= If applicable, 0= If not ΔTloc Change in average temperature (ΔT) at wetland site (°C) Agricultural 1= If applicable, 0= If not Ploc Long term precipitation average for wetland (mm/yr) Fishery 1= If applicable, 0= If not ΔPloc Change in average precipitation (ΔP) at wetland site (mm/yr) Water supply 1= If applicable, 0= If not PET Potential evapotranspiration (mm/yr), calculated as: PET = 325+21×T+0.9×T2 Other Other water usage Aridity Long-term aridity index, calculated as: Aridity = P/PET Input water source River 1= If applicable, 0= If not Climate zone Climate zone based on UNEP: arid (A.) if Aridity index 0.03 to <0.2; semi-arid (Sa.) if Aridity index 0.2 to <0.5; dry sub-humid (Dh.) if Aridity index 0.5 to <0.65; humid if the Aridity index >0.65 Spring 1= If applicable, 0= If not Precipitation 1= If applicable, 0= If not Elevation Elevation (m above sea level) of wetland site Water output Out-River 1= If applicable, 0= If not Area Maximum area of wetland (km2) Evaporation 1= If applicable, 0= If not