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Changelog

Source: NEWS.md

climatekit 0.2.2

CRAN release: 2026-09-09

This release corrects three defects that produced wrong numbers in default code paths. All three were found by an audit that checked each index against its published definition rather than against the package’s own tests.

Bug fixes

  • ck_spei() with the default distribution = "log-logistic" did not return a standardised index. On an 80-year synthetic series it gave mean 1.61 and standard deviation 3.10, where a standardised index is standard normal by construction. Two errors in the L-moment fit were responsible: the shape parameter was computed as tau3 * pi / (3 * sin(tau3 * pi / 3)) instead of 1 / tau3, and the scale parameter omitted a factor of the shape parameter (Vicente-Serrano et al. 2010, appendix). Fitting to data simulated from a known log-logistic now recovers its parameters; output is mean 0.00 and standard deviation 0.99. ck_spi() and distribution = "gev" were unaffected.
  • The log-logistic fit now also rejects an L-skewness outside (0, 1), the range in which a three-parameter log-logistic exists. Calendar months whose water balance is symmetric or left-skewed return NA with a warning instead of a value drawn from a distribution that does not describe them. Use distribution = "gev" for such series.
  • ck_ehf() had the two Excess Heat Factor terms the wrong way round. It computed max(EHIsig, 1) * EHIaccl; Nairn and Fawcett (2013) define EHIsig * max(EHIaccl, 1). The consequence was that the sign of the EHF was set by acclimatisation rather than by heat, so any spell warmer than the preceding 30 days counted as a heatwave whether or not it was hot. On a 30-year synthetic series 5,455 days were flagged where 540 should have been, and 4,915 of those were below the reference 95th percentile.
  • Extraterrestrial radiation selected the polar-day and polar-night cases by hemisphere rather than by the sunset hour angle, so it returned negative radiation at 80 degrees N in December and zero at 80 degrees S in December, when that is the polar-day maximum. At 80 degrees N on 21 December ck_pet_pm() returned 4,619,067 mm/day. The hour-angle argument is now clamped to [-1, 1], which resolves both poles correctly and stops acos() emitting “NaNs produced” warnings. This affected ck_pet(), ck_pet_pm(), and any ck_spei() built on their output, at latitudes beyond about 66.5 degrees.
  • ck_max_5day_precip() returned the sum of a short period as though it were a five-day maximum. A period of fewer than five days now returns NA.

Input validation

Physically impossible input was previously accepted and computed on. This mattered most for missing-data sentinels such as -999, which networks including GHCN use and which were being counted as frost days and subtracted from rainfall totals.

  • Negative precipitation is now an error, with a message pointing at sentinel values as the usual cause.
  • A tmin above tmax is now an error; it means the two columns have been swapped or the data are corrupt. Previously ck_diurnal_range() returned a negative range.
  • Temperatures outside -100 to 70 degrees C now warn. The records are -89.2 and 56.7, so anything beyond that range is almost certainly a sentinel rather than an observation.

climatekit 0.2.1

Bug fixes

Deprecations

  • clear_cache() is deprecated and will be removed in 0.4.0. It warns and returns FALSE invisibly. climatekit performs no I/O and has never written a cache, so the function never had anything to clear. Clear cached weather data with the package that downloaded it.
  • tools is no longer a dependency; it was needed only by clear_cache().

Documentation

  • ck_dry_days() and ck_wet_days() now state their ‘ETCCDI’ codes and warn about the two acronym collisions in the literature: CWD is both consecutive wet days and cold-wave duration, and CDD is both consecutive dry days and cooling degree days. ck_compute() keeps the meaning each ck_* function already carried, and additionally accepts the unambiguous aliases "consecutive_wet_days", "consecutive_dry_days", "cold_wave_duration", "cdd" and the matching cold-wave names.

climatekit 0.2.0

CRAN release: 2026-05-09

Bug fixes

  • ck_total_precip() now applies the canonical ‘ETCCDI’ ‘PRCPTOT’ wet-day filter (precipitation >= 1 mm) by default. Pass wet_day_threshold = 0 to recover the previous raw-sum behaviour.
  • ck_first_frost() and ck_last_frost() gain a lat argument and use hemisphere-appropriate cutoffs. Southern Hemisphere users no longer get silent NA results.
  • ck_branas() gains a lat argument; Southern Hemisphere growing season is now October-February of the following year.
  • ck_precip_intensity() (SDII) returns NA for periods with no valid observations rather than NaN.

In-base bootstrap (Zhang 2005)

  • ck_tx10p(), ck_tn10p(), ck_tx90p(), ck_tn90p() gain a bootstrap = FALSE argument. When TRUE, the leave-one-out resampling of Zhang et al. (2005) is applied to remove self-inclusion bias for analysis years inside the reference period. This is the canonical ‘climdex.pcic’ / ‘climpact’ behaviour and is required for climate-change attribution work spanning the base period.

ET-SCI heatwave family extensions

  • ck_hwm(), ck_hwa(), ck_cwm(), ck_cwa() gain a mode = c( "excess", "absolute") argument. "excess" (default) preserves the existing ‘ET-SCI’ / ‘climpact’ convention. "absolute" returns mean / peak raw temperature on event days, matching Perkins-Alexander (2013).
  • New function ck_ehf() implements the Excess Heat Factor of Nairn and Fawcett (2013), the Australian Bureau of Meteorology operational heatwave metric. Three annual statistics are exposed via stat = c("max", "n_positive", "sum_positive").

SPI / SPEI distribution choice

  • ck_spi() gains distribution = c("gamma", "pearsonIII"). Pearson III is preferred in arid regions where the wet-day distribution is highly skewed (Stagge et al. 2015).
  • ck_spei() gains distribution = c("log-logistic", "gev"). GEV is fitted via Hosking (1985) L-moments.

FAO-56 Penman-Monteith reference ET

  • New function ck_pet_pm() implements the FAO-56 Penman-Monteith reference evapotranspiration (Allen et al. 1998), the international standard. Optional inputs include relative humidity, wind speed, incoming solar radiation, and elevation; FAO-56 fallbacks are used where these are unavailable. ck_pet() remains as the simpler temperature-only Hargreaves estimator.

ETCCDI canonical 27 coverage

ET-SCI heatwave and cold-wave families

  • Added 10 new functions implementing the ‘ET-SCI’ heatwave and cold-wave families on a calendar-day percentile base. Heatwave family: ck_hwn(), ck_hwf(), ck_hwd(), ck_hwm(), ck_hwa() (number, frequency, duration, magnitude, amplitude). Cold-wave duals: ck_cwn(), ck_cwf(), ck_cwd(), ck_cwm(), ck_cwa().
  • The ‘CWD’ acronym is used by both ‘ETCCDI’ (Consecutive Wet Days) and ‘ET-SCI’ (Cold Wave Duration). ck_cwd() here is the ET-SCI cold-wave version; ck_wet_days() is the ETCCDI precipitation index. Both function-level documentation pages cross-reference the other.

Discovery surfaces

  • ck_etccdi_27() returns the canonical 27 ‘ETCCDI’ indices as a data frame with code, name, variable, unit, definition, ck_function, and status columns. Use it to audit coverage or to locate the function for a given short code.
  • ck_catalogue() returns the full implementation catalogue (51 rows). ck_browse(sector, standard, search) filters by sector (‘agriculture’, ‘health’, ‘water’, ‘energy’), standard (‘ETCCDI’, ‘ET-SCI’, ‘agroclimatic’, etc.), or free-text search.

Gridded support

  • ck_apply_grid(x, fun, dates, ...) applies any ck_* function over the cells of a ‘terra’ ‘SpatRaster’ and returns a SpatRaster with one layer per output period.
  • ck_from_netcdf(path, var) is a thin convenience wrapper around terra::rast() for ‘netCDF’ inputs with file-existence and argument validation.
  • ‘terra’ and ‘ncdf4’ are in ‘Suggests’; loading climatekit alone does not pull them in.

Documentation

  • inst/CITATION provides ‘bibentry’ records for the package and for Alexander et al. (2006) and Zhang et al. (2011).
  • ‘CITATION.cff’ at the repository root supports GitHub’s citation widget.
  • New vignette climdex-migration documents the function-name crosswalk from ‘climdex.pcic’ to climatekit, plus interface-shift notes (numeric-vector inputs, tidy data-frame outputs, default reference period).

Documented limitations

  • The percentile-based indices use the standard ±2-day calendar window but do not implement the Zhang et al. (2005) in-base bootstrap. Years inside the reference period therefore have a small self-inclusion bias. This is documented in each function’s documentation page.

climatekit 0.1.0

CRAN release: 2026-03-23

  • Initial release.
  • 10 temperature indices: frost days, ice days, summer days, tropical nights, growing season length, heating/cooling/growing degree days, diurnal temperature range, warm spell duration.
  • 8 precipitation indices: consecutive dry/wet days, total precipitation, heavy/very heavy precipitation days, max 1-day and 5-day precipitation, precipitation intensity (SDII).
  • 3 drought indices: Standardized Precipitation Index (SPI), Standardized Precipitation-Evapotranspiration Index (SPEI), potential evapotranspiration (Hargreaves method).
  • 5 agroclimatic indices: Huglin, Winkler, Branas, first/last frost dates.
  • 4 comfort indices: wind chill, heat index, humidex, fire danger index.
  • Generic dispatcher ck_compute() for programmatic index selection.
  • ck_available() and ck_metadata() for index discovery.
  • ck_convert_temp() for temperature unit conversion.