library(emphatic)
sydney_rain |> head(15)
#>    Year   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec
#> 1  1960  81.6  85.8  50.4  34.7 123.3  96.1 135.7  48.2  58.5 289.7  68.9 269.8
#> 2  1961  50.9  83.7  56.4 107.4  33.0  47.8  45.6 240.6  58.0  63.1 518.8 149.1
#> 3  1962 115.4 134.5  64.2  57.0 309.0   3.3  67.5 132.8  82.8  21.5  13.2 132.8
#> 4  1963 120.1  84.7 389.7 284.1 252.1 250.3  82.8 272.7  23.2  67.2  35.6 226.5
#> 5  1964  17.6  31.1 180.7    NA    NA    NA    NA    NA    NA    NA  24.2  20.1
#> 6  1965  27.5  11.4   8.2  92.5  55.9 229.0  83.3  18.9 106.8 199.2  43.7  64.7
#> 7  1966  26.6 145.6 140.1 265.9  77.3 143.1  17.6  82.1  65.4  56.6 191.2  92.4
#> 8  1967 179.9 155.5 127.3  47.2  52.8 271.3  26.8 198.4 105.3  84.4  88.0  53.9
#> 9  1968 131.9  13.0 125.8  13.3 108.2  30.4  69.9  38.7   1.6   6.0  19.0  88.9
#> 10 1969  42.7 230.9 108.3 151.6  59.9 215.8  50.8  39.7  81.9  48.0 274.6  36.4
#> 11 1970 153.1  58.6    NA  51.0  10.2  33.9   3.6  40.6 152.3  21.9 121.7 263.9
#> 12 1971 161.8 167.1  66.3  65.8 107.2  62.8  25.9 122.6  70.9   2.3  77.5 133.1
#> 13 1972 347.8  99.9 164.1  82.5  93.8 130.5   6.1  33.0  13.4 157.2  65.8  24.6
#> 14 1973 237.8 301.5  96.8  91.7  28.5  92.1 116.5  92.3  78.1 155.5 119.5  33.2
#> 15 1974 230.8 109.1 320.8 170.8 230.8 192.4  11.0 198.6  60.2  70.2  40.4    NA
Average monthly rainfall during the period 1960 - 2023
(mean_rain <- mean(unlist(sydney_rain[,-1]), na.rm = TRUE))
#> [1] 103.3679
 
Floods in NSW
Years in which flooding occurred in New South Wales according to wikipedia
flood_years <- c(1970, 1971, 1984, 1986, 1990, 1996, 1998, 2007, 2012, 2013, 2015, 2016, 2020, 2021, 2022)
 
Highlight months with above average rainfall and mark years in which
flooding occurred
sydney_rain |>
  hl(
    ggplot2::scale_colour_gradient2(na.value = 'white', low = 'white', 
                                    high = 'darkgreen', midpoint = mean_rain), 
    cols = Jan:Dec
  ) |>
  hl('skyblue', rows = Year %in% flood_years, cols = 'Year') |>
  hl_adjust(na = '') |>
  as_svg(height = 1300)