Portland Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Portland, Victoria, Australia. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Now, let's break down all the details for a clearer picture.

On average, Portland receives a reasonable amount of rainfall, with an annual precipitation of 856 mm (34 in).

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Portland can be quite wet during August, receiving approximately 116 mm (4.6 in) of precipitation over 10 rainy days.

In contrast February, experiences much drier conditions, with 36 mm (1.4 in) of rainfall, spread across 8 rainy days.

August, the wettest month, has a maximum daytime temperature of 15°C (59°F). During the driest month February you can expect a temperature of 21°C (70°F). For more detailed insights into the city's temperatures, visit our Portland Temperature page.

Portland's average annual precipitation is 856 mm (34 in). Let's compare this to some popular worldwide tourist destinations:

In Lisbon, Portugal, the average annual precipitation is 774 mm (30 in), characterized by wet winters and dry summers typical of the Mediterranean climate.

Osaka, Japan, experiences 1507 mm (59 in) of rainfall annually, spread across the year with wetter summers.

In Tokyo, Japan, the average annual precipitation is 1528 mm (60 in), with significant summer rains due to typhoon season.

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 Portland:

• 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.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

For more detailed information about Portland's weather, including sunshine hours, humidity levels, and temperature data, visit our Portland Climate page.