ERA-5 Raster Extraction
Frank Donnelly, Head of GIS & Data Services
Brown University Library
Dec 16, 2025 / revised Jan 21, 2026
https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels-monthly-means?tab=overview
Overlay geopackage or shapefile of point observations over an ERA-5 raster of monthly temperature or precipitation, extracts the values from each band, converts units, and output results to CSV. Also stores the value of a specific month / year as a dedicated value that matches a date in the input file.
- Monthly Average 2m tempearture is in degrees Kelvin, program converts to Celsius
- Monthly Total precipitation is in meters, program converts to millimeters
Assumptions:
- Input files are stored in the input subfolder
- ERA raster is a monthly grib file of a single variable (temp OR precip)
- All months for a given time period were downloaded, with no gaps
- Raster and point files are in the WGS 84 CRS
- Point file is a geopackage or shapefile
- Point file includes a unique ID, a name, and an observation date
- Point observation date is stored as YYYY-MM-DD or DD-MM-YYYY
- Points that fall outside the raster are assigned null values
- Points with an observation date outside the time frame will have values recorded, but matching date value will be null
