ck_huglin: Huglin Heliothermal Index

In climatekit: Unified Climate Indices for Temperature, Precipitation, and Drought

Huglin Heliothermal Index

Description

The Huglin index is used in viticulture to characterise the thermal potential of a region for grape growing. It is computed over the growing season (April 1 to September 30 in the Northern Hemisphere; October 1 to March 31 in the Southern Hemisphere).

Usage

ck_huglin(tmin, tmax, dates, lat)

Arguments

tmin	Numeric vector of daily minimum temperatures (degrees C).
tmax	Numeric vector of daily maximum temperatures (degrees C).
dates	Date vector of the same length as tmin.
lat	Numeric. Latitude in decimal degrees (used to determine hemisphere and day-length coefficient).

Value

A data frame with columns period, value, index, and unit.

References

Huglin, P. (1978). Nouveau mode d'evaluation des possibilites heliothermiques d'un milieu viticole. Comptes Rendus de l'Academie d'Agriculture de France, 64, 1117-1126.

Examples

dates <- seq(as.Date("2024-04-01"), as.Date("2024-09-30"), by = "day")
set.seed(42)
tmin <- rnorm(length(dates), mean = 12, sd = 3)
tmax <- tmin + runif(length(dates), 8, 15)
ck_huglin(tmin, tmax, dates, lat = 45)

climatekit documentation built on May 9, 2026, 5:08 p.m.