An R package to download the most up to date of these climate indices:
For the development version
install.packages("rsoi")
library(rsoi)
library(tibble)Download Oceanic Nino Index data
oni <- download_oni()
head(oni)
#> # A tibble: 6 × 7
#>    Year Month Date       dSST3.4   ONI ONI_month_window phase             
#>   <int> <ord> <date>       <dbl> <dbl> <chr>            <fct>             
#> 1  1950 Jan   1950-01-01   -1.62 NA    <NA>             <NA>              
#> 2  1950 Feb   1950-02-01   -1.32 -1.34 JFM              Cool Phase/La Nina
#> 3  1950 Mar   1950-03-01   -1.07 -1.17 FMA              Cool Phase/La Nina
#> 4  1950 Apr   1950-04-01   -1.11 -1.18 MAM              Cool Phase/La Nina
#> 5  1950 May   1950-05-01   -1.37 -1.07 AMJ              Cool Phase/La Nina
#> 6  1950 Jun   1950-06-01   -0.74 -0.85 MJJ              Cool Phase/La NinaAnd a quick plot to illustrate the data:
barcols <- c('#edf8b1','#7fcdbb','#2c7fb8')
barplot(oni$ONI, names.arg = oni$Date, ylab = "Oceanic Nino Index" , 
    col = barcols[oni$phase], border = NA, space = 0,
    xaxt = "n")
The idea for this package borrows heavily from the rpdo
package. rsoi now supercedes rpdo as a source
of data in R for Pacific Decadal Oscillation.