rdwd is an R package to select, download and read climate data from the German Weather Service (Deutscher Wetterdienst, DWD).
The DWD provides thousands of datasets with weather observations online at opendata.dwd.de.
Since May 2019, rdwd also supports reading the Radolan (binary) raster data at grids_germany.

rdwd is available on CRAN:

It has been presented at FOSDEM 2017 and UseR!2017 in Brussels and e-Rum2020, featured in Rstudio's data package list and written about in OSOR.

A website with more information, examples, use cases and an interactive map of the DWD stations can be found at https://bookdown.org/brry/rdwd

Usage for observational weather data from the measuring stations usually looks something like the following:

# Download and install (once only):
install.packages("rdwd")

# Load the package into library (needed in every R session):
library(rdwd)

# select a dataset (e.g. last year's daily climate data from Potsdam city):
link <- selectDWD("Potsdam", res="daily", var="kl", per="recent")

# Actually download that dataset, returning the local storage file name:
file <- dataDWD(link, read=FALSE)

# Read the file from the zip folder:
clim <- readDWD(file, varnames=TRUE)

# Inspect the data.frame:
str(clim)

For data interpolated onto a 1 km raster, including radar data up to the last hour, see the corresponding chapter on the website.

If you're new to R, these links might help you to get started:

• install R & Rstudio
• brief introduction to R
• very large set of slides I use for my courses

back to rdwd:

install.packages("rdwd")

rdwd::updateRdwd()
# checks version and (if needed) calls  remotes::install_github("brry/rdwd", build_vignettes=TRUE)

Suggested (not mandatory) dependencies:

install.packages("rdwd", dependencies="Suggests") 

• RCurl for indexFTP and selectDWD(..., current=TRUE)
• data.table, bit64 for readDWD(..., fread=TRUE)
• raster, R.utils, ncdf4, dwdradar for readDWD with gridded data
• readr for readDWD.stand(..., fast=TRUE)
• knitr, rmarkdown, testthat, roxygen2, devtools, remotes, XML for local testing, development and documentation
• leaflet, OSMscale, sp for interactive/static maps, see OSMscale installation tips

Note: on Linux (Ubuntu), install RCurl via the terminal (CTRL+ALT+T, note lowercase rcurl):

sudo apt install r-cran-rcurl