ZAMG temp graphic

#load libraries
library(httr)
library(jsonlite)
library(ggplot2)

#get data from ZAMG API
importTempPerDay = GET("https://dataset.api.hub.zamg.ac.at/v1/station/historical/klima-v1-10min?parameters=TL&start=2023-04-07T00:00&end=2023-04-08T00:00&station_ids=5925")
#convert to char
dataImportTempPerDay <- fromJSON(rawToChar(importTempPerDay$content))

#create dataframe
dfTempPerDay <- data.frame(dateTime = strptime(paste(as.Date(paste(strtrim(dataImportTempPerDay$timestamps,10),substring(dataImportTempPerDay$timestamps,first=12,last=16),sep=" "),format="%Y-%m-%d %H:%M"),substring(dataImportTempPerDay$timestamps,first=12,last=16),sep= " "), "%Y-%m-%d %H:%M"),
temp = dataImportTempPerDay$features$properties$parameters$TL$data[[1]])

#plot graph
ggplot(dfTempPerDay,aes(dateTime,temp)) + geom_line(color="blue") + geom_label(data=dfTempPerDay[which.max(dfTempPerDay$temp), ],label=paste("Tmax = ",max(dfTempPerDay$temp), "°C"),vjust = -0.25) + ylab("Temperatur (T) °C") + xlab("Zeit") + ggtitle("Temperatur Wien - Innere Stadt")