I’m trying to download and parse GeoTiff files and extract alphanumeric data from them. The files are provided here:

https://www.wpc.ncep.noaa.gov/heatrisk/data.html

The files are categorical projections of heat risk (e.g., “High”, “Very High”, etc.) at various California substate geographies. The data I want are the projections and geo IDs (e.g., county names) associated with each projection, not raster data (for now).

(Note: the .kml files provided on the data page are empty, per correspondence with NWS.)

Downloading the .tif files

This code appears to work:

#Load Packages
#install.packages("raster")
#install.packages("terra")
#install.packages("vapour")

library(raster)
library(httr)
library(terra)


#Read In GeoTiff Files

#Base URL
base_url <- https://www.wpc.ncep.noaa.gov/heatrisk/data/

#Function to Read in Files
download_heatrisk_geotiff <- function(day_number) {
  url <- paste0(base_url, "?day=", day_number)
  response <- GET(url)
  
  if (status_code(response) == 200) {
    # Parse the TIFF content
    tif_content <- content(response, "text")
    
    # Save KML content to a file
    writeLines(tif_content, paste0(getwd(), "/data/HeatRisk_", day_number, "_Mercator.tif"))
    cat(paste0("Downloaded HeatRisk_", day_number, "_Mercator.tifn"))
  } else {
    cat(paste0("Error downloading HeatRisk_", day_number, "_Mercator.tifn"))
  }
}

# Download .tif files for individual days
for (day in 1:7) {
  download_heatrisk_geotiff(day)
}
**Image of downloaded files**

It's not clear that the data I want is in the downloaded files. 
[![Screenshot of downloaded .tif files][1]][1]

Extracting Data

#Extract Data
geotiff_file <- raster(paste0(getwd(), "/data/HeatRisk_", day_number, "_Mercator.tif"))
geotiff_file2 <- terra::readValues(paste0(getwd(), "/data/HeatRisk_", day_number, "_Mercator.tif"))
geotiff_file3 <- vapour::vapour_read_raster(paste0(getwd(), "/data/HeatRisk_", day_number, "_Mercator.tif"))

I’ve already consulted these pages:

• https://inbo.github.io/tutorials/tutorials/spatial_standards_raster/

• R: reading geotiff data straight from web url (httr::GET raw content)

• How to read a GeoTIFF file and return in a specific datatype in R language?

Thanks!