This article shows a quick example of how to download INMET station data and estimate reference evapotranspiration (ETo) using FAO-56, followed by the calculation of the design ETo.
Before downloading data, you can check the available weather stations with:
see_stations_info()
#> # A tibble: 564 × 8
#> station_municipality uf situation_operation latitude_degrees
#> <chr> <chr> <chr> <dbl>
#> 1 Abrolhos BA breakdown -18.0
#> 2 Acarau CE breakdown -3.12
#> 3 Afonso Claudio ES operating -20.1
#> 4 Agua Boa MT operating -14.0
#> 5 Agua Clara MS operating -20.4
#> 6 Aguas Emendadas DF operating -15.6
#> 7 Aguas Vermelhas MG operating -15.8
#> 8 Aimores MG operating -19.5
#> 9 Alegre ES operating -20.8
#> 10 Alegrete RS operating -29.7
#> # ℹ 554 more rows
#> # ℹ 4 more variables: longitude_degrees <dbl>, altitude_m <dbl>,
#> # operation_start_date <dttm>, station_code <chr>Let’s download daily meteorological data for one stations between January 2000 until March 2025:
df <- BrazilMet::download_AWS_INMET_daily(stations = "A001",
start_date = "2000-01-01",
end_date = "2025-03-31")
#> Downloading data for: 2000
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2000.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2000: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2000.zip'
#> Downloading data for: 2001
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2001.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2001: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2001.zip'
#> Downloading data for: 2002
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2002.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2002: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2002.zip'
#> Downloading data for: 2003
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2003.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2003: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2003.zip'
#> Downloading data for: 2004
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2004.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2004: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2004.zip'
#> Downloading data for: 2005
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2005.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2005: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2005.zip'
#> Downloading data for: 2006
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2006.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2006: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2006.zip'
#> Downloading data for: 2007
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2007.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2007: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2007.zip'
#> Downloading data for: 2008
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2008.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2008: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2008.zip'
#> Downloading data for: 2009
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2009.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2009: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2009.zip'
#> Downloading data for: 2010
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2010.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2010: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2010.zip'
#> Downloading data for: 2011
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2011.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2011: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2011.zip'
#> Downloading data for: 2012
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2012.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2012: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2012.zip'
#> Downloading data for: 2013
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2013.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2013: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2013.zip'
#> Downloading data for: 2014
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2014.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2014: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2014.zip'
#> Downloading data for: 2015
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2015.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2015: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2015.zip'
#> Downloading data for: 2016
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2016.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2016: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2016.zip'
#> Downloading data for: 2017
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2017.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2017: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2017.zip'
#> Downloading data for: 2018
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2018.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2018: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2018.zip'
#> Downloading data for: 2019
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2019.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2019: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2019.zip'
#> Downloading data for: 2020
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2020.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2020: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2020.zip'
#> Downloading data for: 2021
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2021.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2021: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2021.zip'
#> Downloading data for: 2022
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2022.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2022: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2022.zip'
#> Downloading data for: 2023
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2023.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2023: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2023.zip'
#> Downloading data for: 2024
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2024.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2024: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2024.zip'
#> Downloading data for: 2025
#> Warning in utils::download.file(url =
#> paste0("https://portal.inmet.gov.br/uploads/dadoshistoricos/", : URL
#> 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2025.zip': status was
#> 'Failure when receiving data from the peer'
#> Warning in value[[3L]](cond): Failed to download data for year 2025: cannot
#> open URL 'https://portal.inmet.gov.br/uploads/dadoshistoricos/2025.zip'
#> Warning in BrazilMet::download_AWS_INMET_daily(stations = "A001", start_date =
#> "2000-01-01", : No data was downloaded for the specified stations and period.The resulting data frame includes temperature, solar radiation, wind speed, humidity, and atmospheric pressure
Now we use the daily_eto_FAO56() function to estimate daily ETo values:
df$eto <- daily_eto_FAO56(
lat = df$latitude_degrees,
tmin = df$tair_min_c,
tmax = df$tair_max_c,
tmean = df$tair_mean_c,
Rs = df$sr_mj_m2,
u2 = df$ws_2_m_s,
Patm = df$patm_mb,
RH_max = df$rh_max_porc,
RH_min = df$rh_min_porc,
z = df$altitude_m,
date = df$date
)
#> Warning in daily_eto_FAO56(lat = df$latitude_degrees, tmin = df$tair_min_c, :
#> NAs introduced by coercionAnd after the ETo calculation, we use the design_eto() function to estimate the design ETo for irrigation project purpose:
# Ensure date column is in Date format
df$date <- as.Date(df$date)
eto_design <- BrazilMet::design_eto(eto_daily_data = df, percentile = .80)
#> Warning in BrazilMet::design_eto(eto_daily_data = df, percentile = 0.8): It is
#> recommended to use at least 10 years of data to calculate the design reference
#> evapotranspiration.Below is a basic line plot of daily ETo:
The BrazilMet package allows you to download official INMET weather data and compute ETo using the FAO-56 method in a reproducible and efficient way. This is essential for irrigation planning, crop modeling, and climate-based decision support.