Code used for the plot shared in https://twitter.com/matteodefelice/status/1293200381309259782

ecad_plot.R

library(lubridate)
library(tidyverse)
library(zoo)
read_station <- function(filename) {
  read_csv(filename,
    col_types = cols(DATE = col_datetime(format = "%Y%m%d")),
    skip = 20
  )
}
station_files <- c(
  "tx/TX_STAID000037.txt",
  "tx/TX_STAID000737.txt",
  "tx/TX_STAID000786.txt",
  "tx/TX_STAID002207.txt"
)

stn_id <- tribble(
  ~STAID, ~name,
  37, "LYON - ST EXUPERY (FR)",
  755, "EMBRUN (FR)",
  737, "LILLE-LESQUIN (FR)",
  786, "MONTELIMAR (FR)",
  2207, "MONTPELLIER-AEROPORT (FR)"
)

stn_data <- lapply(station_files, read_station) %>%
  bind_rows() %>%
  mutate(
    tmax = ifelse(TX != -9999, TX / 10, NA)
  )

sel <- stn_data %>%
  group_by(STAID, year = year(DATE)) %>%
  summarise(
    n35 = sum((tmax >= 35) & (tmax <37), na.rm = TRUE),
    n37 = sum((tmax >= 37) & (tmax <40), na.rm = TRUE),
    n40 = sum(tmax >= 40, na.rm = TRUE)
  ) %>%
  gather(
    var, ndays, -year, -STAID
  ) %>%
  left_join(
    stn_id,
    by = "STAID"
  )

sel %>%
  dplyr::filter(ndays > 0) %>%
  count(name, var)

g <- ggplot(sel, aes(x = year, y = ndays, fill = var)) +
  geom_bar(
    stat = "identity",
    color = "grey66"
  ) +
  scale_fill_manual(
    values = c("#ffffb2", "#fd8d3c", "#bd0026"),
    labels = c("35 <= TX < 37°", "37 <= TX < 40°", "TX >= 40°"),
    name = ""
  ) +
  hrbrthemes::theme_ipsum_rc() +
  facet_wrap(~name, ncol = 1, scales = "free") +
  labs(
    y = "Number of days"
  ) +
  coord_cartesian(
    xlim = c(1950, 2019)
  ) +
  scale_x_continuous(breaks = c(seq(1950, 2019, 10), 2019))

ggsave("france-tmax.png", width = 8, height = 8)