Rainfall/ Precipitation in Guam, Mariana Islands

• Guam receives 2311.8 mm (91 in) of rainfall per year, or 192.7 mm (7.6 in) per month.
• On average there are 211 days per year with more than 0.1 mm (0.004 in) of rainfall (precipitation) or 17.6 days with a quantity of rain, sleet, snow etc. per month.
• The driest weather is in March when an average of 75.7 mm (3 in) of rainfall (precipitation) occurs.
• The wettest weather is in August when an average of 348.7 mm (13.7 in) of rainfall (precipitation) occurs.

Precipitation Table

	Climate Variable	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec		Annual
	Average Precipitation mm (in)	113 (4.45)	95 (3.7)	75.7 (3)	99.3 (3.9)	153.7 (6.1)	164.3 (6.5)	267.5 (10.5)	348.7 (13.7)	342.6 (13.5)	306.8 (12.1)	208.3 (8.2)	136.9 (5.4)		2311.8 (91)
	Precipitation Litres/m² (Gallons/ft²)	113 (2.77)	95 (2.33)	75.7 (1.86)	99.3 (2.44)	153.7 (3.77)	164.3 (4.03)	267.5 (6.56)	348.7 (8.55)	342.6 (8.4)	306.8 (7.53)	208.3 (5.11)	136.9 (3.36)		2311.8 (56.7)
	Number of Wet Days (probability of rain on a day)	14 (45%)	12 (42%)	12 (39%)	10 (33%)	14 (45%)	18 (60%)	24 (77%)	23 (74%)	23 (77%)	23 (74%)	20 (67%)	18 (58%)		211 (58%)
	Percentage of Sunny (Cloudy) Daylight Hours	53 (47)	53 (47)	71 (29)	65 (35)	62 (38)	61 (39)	44 (56)	46 (54)	41 (59)	46 (54)	54 (46)	53 (47)		55 (45)