Hermiston (OR) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Hermiston, Oregon, United States of America. 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.

Hermiston has a dry climate with very low precipitation, averaging 220 mm (8.7 in) of rain/snowfall annually.

Monthly Precipitation Levels

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

The seasons in Hermiston, bring significant changes in precipitation. The wettest month, December, receives moderate snow/rainfall, with an average of 35 mm (1.4 in) of precipitation. This snow/rainfall is distributed across 14 snowy/rainy days.

In contrast, the driest month, July, experiences much less rainfall, totaling 3 mm (0.1 in) over 2 rainy days. These distinct seasonal differences provide diverse experiences throughout the year.

December, the wettest month, has a maximum daytime temperature of 5°C (41°F). During the driest month July you can expect a temperature of 33°C (91°F). For more detailed insights into the city's temperatures, visit our Hermiston 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.

Hermiston vs World: Rainfall Compared

Hermiston's average annual precipitation is 220 mm (8.7 in). Let's compare this to some popular worldwide tourist destinations:

The city of Rome, Italy, has an average annual precipitation of 832 mm (33 in), spread fairly evenly throughout the year.

In Seoul, South Korea, the average annual precipitation is 1237 mm (49 in), with most rain falling during the summer monsoon season.

Perth, Australia, receives 565 mm (22 in) of rainfall annually, mostly during the winter months.

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.

Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.

Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

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