Five Decadal Trends in Averages and Extremes of Rainfall and Temperature in Sri Lanka

Table 1

Rainfall, temperature measures, and seasons investigated to determine average and extreme trends in Sri Lanka.

Variable	Measure
Rainfall	Seasonal total rainfall
	Seasonal wet days^a
	Number of extreme rainfall values (>1-in-2) in seasons^b
	Seasonal maximum rainfall
	Monthly total rainfall
	Mean and maximum rainfall events of duration 2, 3, 5, and 7 days
	Number of heavy rainfall events (>1-in-2) of duration 2, 3, 5, and 7 days^c
	Mean and maximum number of consecutive dry days
Daily temperature (maximum, minimum, and daily temperature range)	Seasonal average temperature
	Number of extreme temperature values (>1-in-2) in seasons^b
	Maximum and minimum seasonal temperatures
	Monthly average temperature
	Maximum temperature values for events of duration 2, 3, 5, and 7 days
	Number of extreme temperature (>1-in-2) events of duration 2, 3, 5, and 7 days^c
Duration of seasons	Annual (Jan–Dec)
	Southwest monsoon (May–Sep)
	First intermonsoon (Mar–Apr)
	Northeast monsoon (Dec–Feb)
	Second intermonsoon (Oct–Nov)

^aRainfall > trace amount (0.254 mm). ^bThose exceeding the value corresponding to the 1-in-2 recurrence interval for the particular seasonal maximum (Table 1). ^cNumbers of events of heavy rainfall and extreme temperature are those exceeding the value corresponding to a 1-in-2 recurrence interval for the maximum magnitude event of the specific duration 2, 3, 5, and 7 days.