Rainfall/ Precipitation in Walla Walla, Washington, Usa

• Walla Walla, Washington receives 393 mm (15.5 in) of rainfall per year, or 32.8 mm (1.3 in) per month.
• On average there are 108 days per year with more than 0.1 mm (0.004 in) of rainfall (precipitation) or 9 days with a quantity of rain, sleet, snow etc. per month.
• The driest weather is in July when an average of 5 mm (0.2 in) of rainfall (precipitation) occurs.
• The wettest weather is in January & December when an average of 48 mm (1.9 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)	48 (1.89)	38 (1.5)	41 (1.6)	36 (1.4)	38 (1.5)	30 (1.2)	5 (0.2)	8 (0.3)	20 (0.8)	38 (1.5)	43 (1.7)	48 (1.9)		393 (15.5)
	Precipitation Litres/m² (Gallons/ft²)	48 (1.18)	38 (0.93)	41 (1.01)	36 (0.88)	38 (0.93)	30 (0.74)	5 (0.12)	8 (0.2)	20 (0.49)	38 (0.93)	43 (1.05)	48 (1.18)		393 (9.64)
	Number of Wet Days (probability of rain on a day)	14 (45%)	11 (39%)	12 (39%)	9 (30%)	9 (29%)	8 (27%)	3 (10%)	3 (10%)	5 (17%)	9 (29%)	11 (37%)	14 (45%)		108 (30%)
	Percentage of Sunny (Cloudy) Daylight Hours	24 (76)	35 (65)	53 (47)	63 (37)	70 (30)	72 (28)	91 (9)	86 (14)	77 (23)	63 (37)	35 (65)	20 (80)		63 (37)