ck_last_frost: Last Frost Date

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

Last Frost Date

Description

Day of year of the last spring frost (Tmin < 0 degrees C) in each year. Hemisphere is selected by lat: in the Northern Hemisphere the search runs up to July 1 (DOY 183); in the Southern Hemisphere up to October 1 (DOY 274), matching the spring boundary for each.

Usage

ck_last_frost(tmin, dates, lat = 50)

Arguments

tmin	Numeric vector of daily minimum temperatures (degrees C).
dates	Date vector of the same length as tmin.
lat	Numeric. Latitude in decimal degrees, used to select the hemisphere convention. Default 50 (Northern Hemisphere).

Value

A data frame with columns period, value (day of year), date (the frost date), index, and unit.

Examples

dates <- seq(as.Date("2024-01-01"), as.Date("2024-06-30"), by = "day")
set.seed(42)
tmin <- -10 + seq_along(dates) * 0.12 + rnorm(length(dates), sd = 3)
ck_last_frost(tmin, dates)

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