Destination Weather API

Observations

In order to request information about the current weather situation points of interest (POIs) have to be provided. The POIs must be an sf object containing geometries of type POINT or a character vector containing place names (e.g. cities). These POIs are passed to the weather() function, whereby the product parameter is set to "observation":

observation <- weather(
  poi = poi,
  product = "observation"
)

The return value is an sf object, which contains the POINT geometries of the provided POIs and the most recent record on the observed weather. The measurements are taken from the nearest weather observation stations with respect to the POIs. The distance of the stations to the provided POIs is an indicator for the reliabilty of the weather information at each POI. A table of the observed weather near the example POIs:

id	city	distance	daylight	description	sky_info	sky_desc	temperature	temperature_desc	comfort	high_temperature	low_temperature	humidity	dew_point	precipitation_probability	rain_fall	wind_speed	wind_direction	wind_descr	wind_descr_short	uv_index	uv_descr	barometer_pressure	barometer_trend
1	Rönnimoos	0.45	day	Sprinkles. Partly sunny. Mild.	14	Partly sunny	19.00	Mild	19.00	21.5	14.9	73	14.00	97	0.52	12.97	160	South	S	0	Minimal	1014.23	Falling
1	Alpnachstad	11.18	day	Sprinkles. More clouds than sun. Mild.	13	More clouds than sun	18.00	Mild	18.00	NA	NA	88	16.00	NA	NA	12.97	190	South	S	NA	NA	1015.24	Falling
1	Stans	11.74	day	Light rain. Broken clouds. Mild.	15	Broken clouds	18.00	Mild	18.00	NA	NA	83	15.00	NA	NA	3.71	0	North	N	NA	NA	1015.24	Falling
2	Lugano	0.67	day	Broken clouds. Mild.	15	Broken clouds	21.00	Mild	21.00	21.4	17.5	94	20.00	99	2.69	7.41	10	North	N	0	Minimal	1015.24	Steady
2	Locarno-Magadino	19.60	day	Rain. Partly sunny. Mild.	14	Partly sunny	20.00	Mild	20.00	NA	NA	94	19.00	NA	NA	5.56	220	Southwest	SW	NA	NA	1014.23	Steady
2	Locarno-Monti	23.35	day	Rain. Low clouds. Mild.	19	Low clouds	18.72	Mild	18.72	NA	NA	90	17.11	NA	NA	7.41	280	West	W	NA	NA	1015.10	Rising
2	Milan / Malpensa	45.13	day	Broken clouds. Mild.	15	Broken clouds	23.00	Mild	22.75	NA	NA	83	20.00	NA	NA	16.68	130	Southeast	SE	NA	NA	1014.23	Steady
3	Chailly	0.34	day	Heavy rain. Low clouds. Mild.	19	Low clouds	17.11	Mild	17.11	19.8	16.3	95	16.28	99	2.38	3.71	120	Southeast	SE	0	Minimal	1016.20	Rising
4	Kleinhüningen	0.43	day	Rain. Overcast. Mild.	18	Overcast	17.39	Mild	17.39	22.4	14.9	93	16.28	71	0.96	9.27	230	Southwest	SW	0	Minimal	1015.10	Rising
5	Kehrsatz	0.62	day	Light rain. More clouds than sun. Mild.	13	More clouds than sun	18.00	Mild	18.00	18.7	13.3	83	15.00	76	0.58	9.27	180	South	S	0	Minimal	1015.24	Rising
5	Grenchen	29.72	day	Light rain. Scattered clouds. Mild.	9	Scattered clouds	18.00	Mild	18.00	NA	NA	88	16.00	NA	NA	7.41	270	West	W	NA	NA	1015.24	Steady
6	Zürich (Kreis 6) / Oberstrass	0.82	day	Sprinkles. Partly sunny. Mild.	14	Partly sunny	19.00	Mild	19.00	20.5	14.6	78	15.00	94	0.39	9.27	160	South	S	0	Minimal	1015.24	Steady
6	Zurich-Kloten	11.00	day	Scattered showers. Passing clouds. Mild.	7	Passing clouds	19.00	Mild	19.00	NA	NA	78	15.00	NA	NA	16.68	160	South	S	NA	NA	1014.23	Falling
6	Zurich-Kloten	11.34	day	Rain showers. Overcast. Mild.	18	Overcast	17.78	Mild	17.78	NA	NA	91	16.28	NA	NA	5.56	170	South	S	NA	NA	1014.50	Rising
7	Geneva	0.49	day	Lots of rain. Low clouds. Mild.	19	Low clouds	17.11	Mild	17.11	23.0	12.4	92	15.78	99	2.99	14.83	90	East	E	0	Minimal	1013.70	Rising
7	Geneva	4.52	day	Rain showers. Broken clouds. Mild.	15	Broken clouds	17.00	Mild	17.00	NA	NA	100	17.00	NA	NA	5.56	0	North	N	NA	NA	1016.26	Falling
7	Annecy-meythet	31.32	day	Light rain. Overcast. Cool.	18	Overcast	16.61	Cool	16.61	NA	NA	91	15.11	NA	NA	12.97	70	East	E	NA	NA	1015.70	Rising
7	Annecy/Meythet	32.61	day	Light rain. Overcast. Mild.	18	Overcast	17.00	Mild	17.00	NA	NA	88	15.00	NA	NA	12.97	70	East	E	NA	NA	1016.26	Falling
8	Vaduz	0.94	day	Rain. Overcast. Mild.	18	Overcast	18.72	Mild	18.72	22.1	14.1	91	17.22	92	2.54	1.85	40	Northeast	NE	0	Minimal	1014.30	Rising
8	Feldkirch	16.66	day	Light rain. Overcast. Mild.	18	Overcast	19.50	Mild	19.50	NA	NA	86	17.11	NA	NA	1.85	290	West	W	NA	NA	1013.20	Rising
8	Chur	29.72	day	Rain. Overcast. Mild.	18	Overcast	17.78	Mild	17.78	NA	NA	94	16.78	NA	NA	7.41	20	North	N	NA	NA	1014.00	Rising

Print the weather observation information on an interactive leaflet map:

if (requireNamespace("mapview", quietly = TRUE)) {
  m <-
    mapview::mapview(observation,
      zcol = "temperature",
      cex = observation$humidity / 10,
      layer.name = "Observation",
      map.types = c("Esri.WorldTopoMap"),
      homebutton = FALSE
    ) +
    mapview::mapview(poi,
      zcol = "city",
      cex = 1,
      col.region = "black",
      legend = FALSE,
      homebutton = FALSE
    )
  m
}

Forecast

An hourly forecast of the predicted weather for the following seven days can be obtained by setting the product parameter to "forecast_hourly":

forecast <- weather(
  poi = poi,
  product = "forecast_hourly"
)

Print the weather observation information on an interactive leaflet map with popup graphs for temperature and humidity:

Create a list containing the temperature and humidity graphs for every POI:

if (requireNamespace("ggplot2", quietly = TRUE)) {
  g <- lapply(seq_len(nrow(forecast)), function(x) {
    df <- forecast$forecasts[[x]]
    ggplot2::ggplot(df, ggplot2::aes(x = time)) +
      ggplot2::geom_line(ggplot2::aes(y = temperature, color = "Temperature")) +
      ggplot2::geom_line(ggplot2::aes(y = humidity / 5, color = "Humidity")) +
      ggplot2::scale_y_continuous(sec.axis = ggplot2::sec_axis(~ . * 5, name = "Relative humidity [%]")) +
      ggplot2::scale_color_manual(values = c("blue", "red")) +
      ggplot2::labs(y = "Air temperature [°C]", x = "", colour = "") +
      ggplot2::ggtitle(forecast$city[x]) +
      ggplot2::theme_minimal() +
      ggplot2::theme(legend.position = "bottom", panel.background = ggplot2::element_rect(color = NA))
  })
}

Then add list of graphs to the leaflet map using the the popup parameter:

if (requireNamespace(c("ggplot2", "mapview", "leafpop"), quietly = TRUE)) {
  m <-
    mapview::mapview(forecast,
      color = "black",
      col.region = "yellow",
      layer.name = "Weather station",
      zcol = "city",
      map.types = c("Esri.WorldTopoMap"),
      homebutton = FALSE,
      legend = FALSE,
      popup = leafpop::popupGraph(g)
    ) +
    mapview::mapview(poi,
      zcol = "city",
      cex = 1,
      col.region = "black",
      layer.name = "POI",
      legend = FALSE,
      homebutton = FALSE
    )
  m
}

Astronomy

An astronomical forecast is requested by setting the product parameter to "forecast_astronomy":

astronomy <- weather(
  poi = poi,
  product = "forecast_astronomy"
)

Print a table for the sun and moon times of the first example POI, where the nearest station is ‘Emmenbrücke’:

time	sun_rise	sun_set	moon_rise	moon_set	moon_phase	moon_phase_description
2023-09-18	07:07:00	19:33:00	10:33:00	20:47:00	0.079	Waxing crescent
2023-09-19	07:09:00	19:31:00	11:45:00	21:08:00	0.141	Waxing crescent
2023-09-20	07:10:00	19:29:00	12:59:00	21:35:00	0.218	Waxing crescent
2023-09-21	07:11:00	19:27:00	14:14:00	22:11:00	0.310	Waxing crescent
2023-09-22	07:13:00	19:25:00	15:25:00	23:01:00	0.412	First Quarter
2023-09-23	07:14:00	19:23:00	16:26:00	NA	0.521	First Quarter
2023-09-24	07:15:00	19:21:00	17:16:00	00:05:00	0.631	Waxing gibbous
2023-09-25	07:17:00	19:19:00	17:53:00	01:23:00	0.738	Waxing gibbous

Alerts

Current weather alerts, near provided POIs, are obtain by the product alerts:

alerts <- weather(
  poi = poi,
  product = "alerts"
)

This returns an sf object with the POIs and the attribute "alerts", which contains the current weather alerts. If no alerts are recorded near a POI the attribute "alerts" is NULL.

API Reference