Des Moines (WA) Monthly Rainfall & Precipitation
This page shows both the average monthly rainfall and the number of rainy days in Des Moines, Washington State, United States of America. This average is based on long-term data collected between 1990 and 2020. Now, let's explore all the details to give you a full picture.
Des Moines is known for its substantial rain/snowfall, with annual precipitation reaching 1079 mm (42 in). While the overall climate is wet, there are notable seasonal patterns that create interesting contrasts, as demonstrated in our graph below.
Monthly Precipitation Levels
The average number of days each month with precipitation (> 0.2 mm (0.01 in))
Significant seasonal changes in precipitation occur throughout the year. During the wettest month, November receives substantial rainfall, averaging 177 mm (7 in) of precipitation, recorded across 21 rainy days.
In contrast, the driest month, July brings less rainfall, with 14 mm (0.6 in) over 4 rainy days.
November, the wettest month, has a maximum daytime temperature of 11°C (52°F). The city receives 73 hours of sunshine in this period. During the driest month July you can expect a temperature of 25°C (77°F). For more detailed insights into the city's temperatures, visit our Des Moines Temperature page.
Annual Rainfall in the United States of America: City Comparison
The map below shows the annual precipitation across the United States of America. You can also select the different months in case you are interested in a specific month.
heavy rainfall
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Des Moines vs World: Rainfall Compared
Des Moines's average annual precipitation is 1079 mm (42 in). Let's compare this to some popular worldwide tourist destinations:
In Toronto, Canada, annual precipitation averages 964 mm (38 in), with snowy winters and rainy summers.
Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.
Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.
Singapore, situated near the equator, gets 2581 mm (102 in) of rainfall annually, with no distinct dry season and consistent monthly precipitation.
Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.
Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.
Climate change is affecting precipitation patterns worldwide, including Des Moines (WA):
- Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
- Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.
- "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
- The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
- The greatest snowfall recorded was on Mt. Rainier, Washington State, USA—over 31.5 meters (103 feet) fell during the winter of 1972.
For more detailed information about Des Moines (WA)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Des Moines (WA) Climate page.
