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Get started with climaemet

Diego Hernangómez

Source: vignettes/climaemet.qmd

climaemet provides access to meteorological observations, forecasts, alerts and climatology data from the Spanish Meteorological Agency (AEMET). It is part of rOpenSpain, a community that develops R packages for working with Spanish public data.

API key

Get an API key

To download data from AEMET, obtain a free API key from the AEMET OpenData registration page.

Once you have your API key, you can use any of the following methods:

Set the API key with aemet_api_key()

This is the recommended option. Run:

aemet_api_key("YOUR_API_KEY", install = TRUE)

Using install = TRUE stores the API key on your local computer so it is available in future R sessions.

Use an environment variable

Alternatively, set the API key as an environment variable for the current session:

Sys.setenv(AEMET_API_KEY = "YOUR_API_KEY")

You need to run this command again after restarting R.

Modify your .Renviron file

You can also store the API key permanently in .Renviron. Open the file with:

usethis::edit_r_environ()

Then add the following line:

AEMET_API_KEY=YOUR_API_KEY

Data formats

Tabular results

climaemet returns tabular results as tibble objects. The package also infers column types when possible. For example, date and time columns are parsed as date-time objects and numeric columns are parsed as doubles.

The following call returns a tibble:

# Inspect a tibble.

aemet_last_obs("9434")
#> # A tibble: 12 × 25
#>    idema   lon fint                 prec   alt  vmax    vv    dv   lat  dmax ubi      pres    hr
#>    <chr> <dbl> <dttm>              <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <chr>   <dbl> <dbl>
#>  1 9434  -1.00 2026-08-25 23:00:00     0   249   3.4   1      56  41.7   130 ZARAGO…  984.    44
#>  2 9434  -1.00 2026-08-26 00:00:00     0   249   4.8   3.2   111  41.7   108 ZARAGO…  984.    49
#>  3 9434  -1.00 2026-08-26 01:00:00     0   249   4     1.8    92  41.7   110 ZARAGO…  983     53
#>  4 9434  -1.00 2026-08-26 02:00:00     0   249   2.9   1.7    79  41.7    88 ZARAGO…  983.    61
#>  5 9434  -1.00 2026-08-26 03:00:00     0   249   3.5   2.3    99  41.7    75 ZARAGO…  983.    66
#>  6 9434  -1.00 2026-08-26 04:00:00     0   249   3.1   1.9   102  41.7   103 ZARAGO…  983.    66
#>  7 9434  -1.00 2026-08-26 05:00:00     0   249   5.4   3.3   116  41.7   130 ZARAGO…  983.    70
#>  8 9434  -1.00 2026-08-26 06:00:00     0   249   6.2   3.6   134  41.7   150 ZARAGO…  983.    70
#>  9 9434  -1.00 2026-08-26 07:00:00     0   249   6.2   3.7   113  41.7   115 ZARAGO…  982     66
#> 10 9434  -1.00 2026-08-26 08:00:00     0   249   8.8   6.3   141  41.7   138 ZARAGO…  982.    64
#> 11 9434  -1.00 2026-08-26 09:00:00     0   249   9.4   6     127  41.7   125 ZARAGO…  982.    57
#> 12 9434  -1.00 2026-08-26 10:00:00     0   249  10.8   7.1   120  41.7   128 ZARAGO…  982.    49
#> # ℹ 12 more variables: stdvv <dbl>, ts <dbl>, pres_nmar <dbl>, tamin <dbl>, ta <dbl>,
#> #   tamax <dbl>, tpr <dbl>, stddv <dbl>, inso <dbl>, tss5cm <dbl>, pacutp <dbl>, tss20cm <dbl>

Spatial objects with sf

Data-access functions that support return_sf = TRUE can return spatial sf objects. These objects use the EPSG:4326 coordinate reference system (CRS), corresponding to the World Geodetic System 1984 (WGS 84), with unprojected longitude and latitude coordinates:

# You need to install sf if it is not already installed.
# Run install.packages("sf") to install it.

library(ggplot2)
library(dplyr)

all_stations <- aemet_daily_clim(
  start = "2021-01-08",
  end = "2021-01-08",
  return_sf = TRUE
)

ggplot(all_stations) +
  geom_sf(aes(colour = tmed), shape = 19, size = 2, alpha = 0.95) +
  labs(
    title = "Average temperature in Spain",
    subtitle = "8 Jan 2021",
    color = "Mean temp.\n(°C)",
    caption = "Source: AEMET"
  ) +
  scale_colour_gradientn(
    colours = hcl.colors(10, "RdBu", rev = TRUE),
    breaks = c(-10, -5, 0, 5, 10, 15, 20),
    guide = "legend"
  ) +
  theme_bw() +
  theme(
    panel.border = element_blank(),
    plot.title = element_text(face = "bold"),
    plot.subtitle = element_text(face = "italic")
  )
Example: temperature in Spain

Example: temperature in Spain

Additional features

Other package features include:

  • Data functions accept vector inputs where the AEMET OpenData API supports them.
  • get_metadata_aemet() retrieves metadata from arbitrary AEMET OpenData API endpoints.
  • ggclimat_walter_lieth() creates Walter-Lieth climate diagrams and is the default plotting method used by climatogram_normal() and climatogram_period(). Experimental. Set ggplot2 = FALSE to use climatol::diagwl() instead.
  • Plotting functions accept additional options through ....
  • The example datasets climaemet_9434_climatogram, climaemet_9434_temp and climaemet_9434_wind support the plotting examples.