Hermiston (OR) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Hermiston.
Climate overview of Hermiston
Hermiston, Oregon, United States of America, experiences significant temperature variation throughout the year. Summers bring daytime highs of 33°C (91°F) in July, while winters cool to 5°C (41°F) in December.
Rain/snowfall is extremely rare, with only 220 mm (8.7 in) falling across the entire year.
Hermiston Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Hermiston - and find the best time to visit.
Monthly Temperature in Hermiston
Depending on the time of the year, temperatures range from very warm to chilly in Hermiston. Average maximum daytime temperatures range from a very warm 33°C (91°F) in July, the warmest time of the year, to a chilly 5°C (41°F) during cooler months like December.
At night, you can expect temperatures ranging from 15°C (59°F) in July to around -3°C (27°F) during December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Hermiston
Hermiston has a dry climate with very low precipitation, averaging 220 mm (8.7 in) of rain/snowfall annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives moderate snow/rainfall, averaging 35 mm (1.4 in) of precipitation, recorded across 14 snowy/rainy days. In contrast, the driest month July brings less rainfall, with 3 mm (0.1 in) over 2 rainy days. For more details, please visit our Hermiston Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Best Time to Visit Hermiston
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: April, May, June, September and October
- Warmest weather: July and August
- Fewest rainy days: July, August and September
- Seasonal pattern: Very little rainfall year-round, with very warm summers and cold winters
- Coldest conditions: December, with freezing nights around -3°C (27°F).
Frequently asked questions about the climate in Hermiston
What is the best time to visit Hermiston?
April, May, June, September and October typically offer the most optimal weather in Hermiston. In contrast, December tends to have less optimal conditions. Hermiston has very little rainfall year-round, with very warm summers and cold winters.
What temperatures can I expect in Hermiston?
Daytime highs range from 5°C (41°F) in December to 33°C (91°F) in July. Nighttime lows range from -3°C (27°F) to 15°C (59°F). Temperatures vary considerably through the year.
How much rain does Hermiston get?
Annual rainfall is around 220 mm (8.7 in). December is the wettest month with 35 mm (1.4 in), while July is the driest with 3 mm (0.1 in). In the coldest months, precipitation may fall as snow/rain.
Hermiston 3-Day Forecast
Hermiston on the map
Hermiston is highlighted - select any city to see its climate.
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