The best times to visit Lewiston for ideal weather are

May 28th to September 30th

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.



Other Lewiston Travel Info

Weather in Lewiston


Average temperatures in Lewiston vary drastically. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a low chance of precipitation most of the year. The area is less temperate than some — in the 34th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Lewiston, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally early July where highs are regularly around 94.9°F (34.9°C) with temperatures rarely dropping below 55.2°F (12.9°C) at night.

Lewiston Temperatures (Fahrenheit)


Lewiston Temperatures (Celsius)


“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

Lewiston Perceived Temperature (F)


Lewiston Perceived Temperature (C)



Average Lewiston Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 51.8 36.4 29.3
Feb 55.9 40.1 31.3
Mar 59.5 44.6 35.1
Apr 67 50.2 37.3
May 75.1 56.9 41.4
Jun 84.7 65.5 48
Jul 93.6 73.3 54.9
Aug 91.4 70.4 51.9
Sep 87.1 64.6 47.1
Oct 73.2 53.5 40.6
Nov 55.5 41.8 34.3
Dec 47 36.3 30.8

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 11 2.4 -1.5
Feb 13.3 4.5 -0.4
Mar 15.3 7 1.7
Apr 19.4 10.1 2.9
May 23.9 13.8 5.2
Jun 29.3 18.6 8.9
Jul 34.2 22.9 12.7
Aug 33 21.3 11.1
Sep 30.6 18.1 8.4
Oct 22.9 11.9 4.8
Nov 13.1 5.4 1.3
Dec 8.3 2.4 -0.7



Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Lewiston are August, July, and then September. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around mid June. For example, on the week of June 18th there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in mid December with an average of 3 days of significant precipitation the week of December 17th.

When can you find snow in Lewiston? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in Lewiston.

Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in Lewiston (in).

Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 17% 0 5.3
Feb 24% 0 8.7
Mar 21% 0 6
Apr 11% 0 2.8
May 9% 0 1.6
Jun 6% 0 0.8
Jul 1% 0 0.2
Aug 1% 0 0.1
Sep 4% 0 0.6
Oct 13% 0 3.1
Nov 16% 0 3.4
Dec 30% 0 7.4

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 17 0 13.5
Feb 24 0 22.1
Mar 21 0 15.2
Apr 11 0 7.1
May 9 0 4.1
Jun 6 0 2
Jul 1 0 0.5
Aug 1 0 0.3
Sep 4 0 1.5
Oct 13 0 7.9
Nov 16 0 8.6
Dec 30 0 18.8


Humidity and Wind

Lewiston has some very humid months, and dry months in the opposite season. The least humid month is August (28.9% relative humidity), and the most humid month is December (80.9%).

Wind in Lewiston is usually extremely calm. The windiest month is May, followed by April and June. May’s average wind speed of around 3.3 knots (3.7 MPH or 6 KPH) is considered “light air.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in late May where average top sustained speeds reach 11.6 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in Lewiston.

Avg. Relative Humidity


The graph below shows wind speed (max and average) in knots.

Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 1 Barely noticeable 5.5 Light breeze
Feb 1.7 Barely noticeable 7.7 Gentle breeze
Mar 2.1 Barely noticeable 8.4 Light breeze
Apr 3 Barely noticeable 10.2 Gentle breeze
May 3.3 Barely noticeable 10.2 Light breeze
Jun 2.9 Barely noticeable 9.8 Gentle breeze
Jul 2.1 Barely noticeable 8.6 Light breeze
Aug 2.1 Barely noticeable 8.6 Gentle breeze
Sep 2.1 Barely noticeable 8.4 Light breeze
Oct 1.5 Barely noticeable 7.2 Gentle breeze
Nov 1.4 Barely noticeable 6.6 Light breeze
Dec 1.1 Barely noticeable 5.8 Light breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 75.7%
Feb 65.8%
Mar 63.1%
Apr 47.4%
May 39.2%
Jun 34.7%
Jul 31.3%
Aug 28.9%
Sep 32.2%
Oct 52.6%
Nov 72.7%
Dec 80.9%


Is it Safe to Travel to Lewiston?

Our best data indicates this area is generally safe. As of Oct 07, 2019 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Sep 23, 2019.


The Busiest and Least Crowded Months

The busiest month for tourism in Lewiston, CA, US is July, followed by June and August. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Lewiston in December. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month


Most Popular Months to Visit

Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is extrapolated based on nearby areas. Displayed data is calculated relative to the peak, so a score of 36.3 in December means 36.3% of the tourists vs. July.



Overall Lewiston Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderately cold. Highs range from 77.3°F (25.2°C) and 55.1°F (12.8°C) with warmer temperatures in the later months. Rain is somewhat common with 3 to 7 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the least precipitation with 0 to 2 days of precipitation per month. June – August is the busiest season for tourism in Lewiston, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 90.8°F (32.7°C) and 49.8°F (9.9°C), which will feel comfortable given the humidity and wind. It rains or snows a normal amount: 1 to 5 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.

Winter (December through February)

Weather is too cold this time of year in Lewiston to be enjoyable for warm weather travelers. The average high during this season is between 57.1°F (13.9°C) and 44.9°F (7.2°C). On average, it rains or snows a fair amount: 5 to 9 times per month. These times of year are fairly slow with tourists.


Best Times to Travelthe United States › Lewiston, CA, US