Daily Gridded Precipitation Dataset for Ceará (Brazil) at 0.15° Resolution Derived from FUNCEME Rain Gauge Network (1973–Present)

Daily Gridded Precipitation Dataset for Ceará, Brazil (1973–Present) This dataset provides daily precipitation fields for the state of Ceará, northeastern Brazil, interpolated onto a regular grid with spatial resolution of 0.15°. The dataset spans the period from 1973 to present and is derived from the rain gauge network operated by the Fundação Cearense de Meteorologia e Recursos Hídricos. Rainfall observations originate from conventional rain gauges installed across the state and maintained as part of FUNCEME’s operational hydrometeorological monitoring network. The measurements are collected using standard Ville de Paris rain gauges, which are widely used in hydrological monitoring due to their robustness and reliability. Observations are recorded daily with accumulation periods defined from 07:00 local time of the previous day to 07:00 local time of the current day. Consequently, each reported daily value corresponds to the precipitation accumulated between 07:00 and 07:00 local time. Over the historical record, the number of active stations varies as the monitoring network expanded and evolved. In recent years, approximately 550 stations have been operational, providing dense spatial coverage across the state. This relatively high station density allows the construction of spatially continuous precipitation fields suitable for climate monitoring, hydrological analysis, drought assessment, and environmental applications. The number of rain gauges available for interpolation increased substantially over the historical period as the monitoring network expanded across the state. Table 1 summarizes the approximate average number of active rain gauges by decade used in the construction of the gridded precipitation dataset. The network experienced significant growth from the 1970s through the 2000s, reaching more than 500 active stations in recent decades. This dense observational coverage contributes to improved spatial representation of rainfall variability across Ceará. Table 1 - Approximate number of active rain gauges by decade used in the interpolation procedure. Decade Average number of rain gauges 1970s 91 1980s 171 1990s 251 2000s 549 2010s 506 2020s 554 Prior to interpolation, the station observations undergo a series of quality control procedures aimed at identifying and removing spurious or inconsistent records. These procedures include checks for physically unrealistic values, temporal inconsistencies, and other potential observational errors. Suspicious observations are flagged and excluded from the interpolation procedure when necessary. Spatial interpolation of precipitation is performed using ordinary kriging. The spatial dependence structure of rainfall was characterized through an empirical semivariogram, which was fitted using an exponential variogram model. This approach allows the interpolation algorithm to account for the spatial autocorrelation structure of rainfall observations, providing statistically consistent estimates at unsampled locations. The resulting gridded dataset provides daily precipitation values on a regular latitude–longitude grid with spatial resolution of 0.15°, covering the entire territory of Ceará. The dataset is particularly useful for studies of hydroclimatology, drought monitoring, climate variability, agricultural applications, and water resources management in semiarid regions. Users should note that the spatial interpolation accuracy may vary depending on station density and the spatial distribution of rainfall events, particularly during convective precipitation episodes that exhibit strong spatial heterogeneity. Nevertheless, the relatively dense rain gauge network in Ceará provides a robust basis for constructing gridded precipitation estimates over the region. The dataset will be periodically updated as new observations become available and additional quality control procedures are applied.We would like to express our sincere gratitude to Jarbas Camurça for their invaluable technical assistance in data processing/quality control. We also gratefully acknowledge the dedicated network of volunteer observers whose diligent daily recordings from conventional rain gauges made this dataset possible. Their long-term commitment to manual observation is essential to the accuracy and continuity of our climate records. How to cite: Vasconcelos Junior, F. C., Camurça, P. J., Guimarães, S.O., Rodrigues Pereira, J. M., Pinheiro, E., & Martins, E. S. P. R. (2026). Daily Gridded Precipitation Dataset for Ceará (Brazil) at 0.15° Resolution Derived from FUNCEME Rain Gauge Network (1973–Present) (v1.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.19025155