Winthrop Average Rainfall by Month

This page shows the average precipitation (including snowfall) in each month of the year in Winthrop, Washington. It is based on NOAA data for the years 1991–2020.

Average temperature by month

What's the Rainiest Month in Winthrop?

In Winthrop, January has the greatest precipitation of any month. On average, Winthrop gets 2.2 inches of precipitation in January.

However, November is the month with the greatest chance of precipitation. 41.1% of days in November will have at least some rain or snow.

What's the Driest Month in Winthrop?

In Winthrop, August has the least precipitation of any month. On average, Winthrop gets 0.40 inches of precipitation in August.

August is also the month where rain is least common. 12.2% of days in August will have measurable rain.

Month	Precipitation	% Chance
January	2.16 in	39.8
February	1.27 in	30.3
March	1.23 in	25.4
April	0.84 in	21.6
May	1.10 in	24.7
June	1.09 in	24.3
July	0.69 in	14.1
August	0.40 in	12.2
September	0.45 in	14.2
October	1.37 in	27.3
November	1.99 in	41.1
December	2.52 in	43.0
Year	15.04 in	26.5

Weather Station Details

Years	Station	Coordinates
1906–2024	Winthrop 1 WSW	location