Consecutive Wet Days

The number of consecutive wet days (CWD) is similar to the above CDD, the largest number of consecutive days with daily precipitation amount more than 1 mm (or depend on the rain days criteria of the country), within a certain time. Usually the process counts the number of days in the past 90 days to measure the wet level.

How it works

Calculate the number of rain days based on the threshold and calculate the count of the most recent days since a dry day or the most recent consecutive string of days that meet the threshold criteria is summed.

Option for rain day’s threshold: 1, 2.5, 5, 10 or 20 milimeters of rainfall per day.

IF previousCWD == null THEN previousCWD == 0
ELSEIF todayRAIN < 1 AND previousCWD == 0 THEN previousCWD + 1

CWD derived from IMERG data.

About the data

Characteristic	Description
Function	Display daily CWD
Variable	CWD
Geographic coverage	Global 60N-60S, 180W-180E
Spatial resolution	0.1 degree ~ 11.1 km at equator
Temporal resolution	Daily
Format	GeoTIFF
Unit	Number of day

Symbology

The threshold and the symbology for the CWD can follow below color codes and image.

Class	Threshold	Hex	RGB
No Rainfall	0	#cccccc	rgb(204, 204, 204)
Very Short	1 - 5	#ffffcc	rgb(255, 255, 204)
Short	6 - 10	#c6e8b3	rgb(198, 232, 179)
Moderate	11 - 20	#7eccba	rgb(126, 204, 186)
Long	21 - 30	#41b7c4	rgb(65, 183, 196)
Very Long	31 - 60	#2c80b8	rgb(44, 128, 184)
Extreme Wet	+60	#253494	rgb(37, 52, 148)

Data access

Global CWD data available at DEC S3: s3://wbgdecinternal-ntl/climate/products/cwd-imerg.