Climate variables

Climate variables and their acronyms used as independent variables in regression analyses (from Rehfeldt and others 2006).

Acronym	Definition
MAT	mean annual temperature
MTCM	average temperature in the coldest month
MMIN	minimum temperature in the coldest month
MTWM	mean temperature in the warmest month
MMAX	maximum temperature in the warmest month
MAP	mean annual precipitation
GSP	growing season precipitation, April through September
TDIFF	summer-winter temperature differential, MTWM-MTCM
DD5	degree-days > 5 °C
DD0	degree-days < 0 °C
MINDD0	minimum degree-days < 0 °C
SDAY	Julian date of the last freezing date of spring
FDAY	Julian date of the first freezing date of autumn
FFP	length of the frost-free period
D100	Julian date the sum of degree-days > 5 °C reaches 100
AMI	annual moisture index, DD5/MAP
SMI	summer moisture index, GSDD5/GSP
PRATIO	ratio of summer precipitation to total precipitation, GSP/MAP

Interactions: MAP x DD5, MAP x MTCM, GSP x MTCM, GSP x DD5, DD5 x MTCM, MAP x TDIFF, GSP x TDIFF, MTCM/MAP, MTCM/GSP, AMI x MTCM, SMI x MTCM, TDIFF/MAP, TDIFF/GSP, PRATIO x MTCM, PRATIO x DD5

Copyright: Public Domain