Lewiston (ID) Weather & Climate: Best Time to Visit

Average temperatures, rainfall, sunshine and the best time to visit Lewiston.

Full Climate overview Temperature Rainfall
Current conditions Lewiston –  

Climate overview of Lewiston

Temperatures in Lewiston, Idaho, United States of America, vary greatly throughout the year. July is the hottest month at 34°C (93°F), while December is the coldest at 5°C (41°F).

The city tends toward dry conditions, with around 341 mm (13 in) of rain/snowfall per year. It does, however, have very little rainfall for most of the year, with very warm summers and cold winters.

Lewiston Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Lewiston - and find the best time to visit.

Monthly Temperature in Lewiston

The climate in Lewiston is known for significant temperature differences throughout the year, making the weather dynamic. Typically, average maximum daytime temperatures range from a very warm 34°C (93°F) in July to a chilly 5°C (41°F) in the coolest month, December.

Nights vary from 16°C (61°F) in July to around -1°C (30°F) during the colder months.

Check out our detailed temperature page for more information.

Temperature ranges by month

Rainfall in Lewiston

Lewiston has a relatively dry climate with low precipitation, averaging 341 mm (13 in) of rain/snowfall annually. The climate in Lewiston shows significant variation throughout the year. Expect moderate rainfall in March, the wettest month, with an average of 44 mm (1.7 in) of precipitation over 17 rainy days.

In contrast, the driest month July offers drier and sunnier days, with around 11 mm (0.4 in) of rainfall over 4 rainy days. For more details, please visit our Lewiston Precipitation page.

The mean monthly precipitation over the year, including rain, hail, and snow

Best Time to Visit Lewiston

The most comfortable overall weather for exploring Lewiston is usually found in May, June, September and October. Conditions are generally least comfortable in January, July, November and December.

Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.

  • Best overall: May, June, September and October
  • Warmest weather: July and August
  • Fewest rainy days: July, August and September
  • Seasonal pattern: Very little rainfall for most of the year, with very warm summers and cold winters
  • Coldest conditions: December, with freezing nights around -1°C (30°F).

Frequently asked questions about the climate in Lewiston

What is the best time to visit Lewiston?

May, June, September and October typically offer the most optimal weather in Lewiston. In contrast, January, July, November and December tend to have less optimal conditions. Lewiston has very little rainfall for most of the year, with very warm summers and cold winters.

What temperatures can I expect in Lewiston?

Daytime highs range from 5°C (41°F) in December to 34°C (93°F) in July. Nighttime lows range from -1°C (30°F) to 16°C (61°F). Temperatures vary considerably through the year.

How much rain does Lewiston get?

Annual rainfall is around 341 mm (13 in). March is the wettest month with 44 mm (1.7 in), while July is the driest with 11 mm (0.4 in).

Lewiston 3-Day Forecast

Lewiston on the map

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