% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/temperature.R
\name{ck_tnn}
\alias{ck_tnn}
\title{Annual or Monthly Minimum of Daily Minimum Temperature (TNn)}
\usage{
ck_tnn(tmin, dates, period = "annual")
}
\arguments{
\item{tmin}{Numeric vector of daily minimum temperatures (degrees C).}

\item{dates}{Date vector of the same length as \code{tmin}.}

\item{period}{Character. Aggregation period: \code{"annual"} (default) or
\code{"monthly"}.}
}
\value{
A data frame with columns \code{period}, \code{value}, \code{index}, and \code{unit}.
}
\description{
ETCCDI canonical index TNn. The minimum value of daily minimum
temperature (Tmin) within each reporting period (coldest night).
}
\examples{
dates <- as.Date("2024-01-01") + 0:9
tmin <- c(-2, 3, -1, 5, -8, 0, 2, -12, 1, -1)
ck_tnn(tmin, dates)
}
