2025 Compare Climate & Weather:
Boulder, CO vs Sisters, OR

Highlights

On average, there are 162 sunny days per year in Sisters. Boulder averages 245 sunny days per year. The US average is 205 sunny days.

Sisters, Oregon gets 11.4 inches of rain, on average, per year. Boulder, Colorado gets 18.1 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Sisters averages 16.1 inches of snow per year. Boulder averages 71.1 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Sisters, Oregon
Summer High: the July high is around 84.2 degrees
Winter Low: the January low is 23.2
Rain: averages 11.4 inches of rain a year
Snow: averages 16.1 inches of snow a year

Boulder, Colorado
Summer High: the July high is around 88.1 degrees
Winter Low: the January low is 18.9
Rain: averages 18.1 inches of rain a year
Snow: averages 71.1 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Sisters is 7.0 (10=best), which means it is less comfortable than most places in Oregon.

The annual BestPlaces Comfort Index for Boulder is 7.1 (10=best), which means it is about average compared to other places in Colorado.

Today's Weather - Boulder, CO

44°F

Today's Weather - Sisters, OR

70°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Boulder / Sisters

July is the hottest month for Boulder with an average high temperature of 88.1°, which ranks it as about average compared to other places in Colorado. In Boulder, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Boulder are September, June and May.

July is the hottest month for Sisters with an average high temperature of 84.2°, which ranks it as warmer than most places in Oregon. In Sisters, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Sisters are September, June and August.

December has the coldest nighttime temperatures for Boulder with an average of 18.3°. This is one of the warmest places in Colorado.

December has the coldest nighttime temperatures for Sisters with an average of 21.4°. This is colder than most places in Oregon.

In Boulder, there are 32.4 days annually when the high temperature is over 90°, which is about average compared to other places in Colorado.

In Sisters, there are 19.7 days annually when the high temperature is over 90°, which is hotter than most places in Oregon.

In Boulder, there are 151.2 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in Colorado.

In Sisters, there are 178.7 days annually when the nighttime low temperature falls below freezing, which is one of the coldest places in Oregon.

In Boulder, there are 5.5 days annually when the nighttime low temperature falls below zero°, which is warmer than most places in Colorado.

In Sisters, there are 2.8 days annually when the nighttime low temperature falls below zero°, which is colder than most places in Oregon.

May is the wettest month in Boulder with 2.5 inches of rain, and the driest month is January with 0.6 inches. The wettest season is Summer with 37% of yearly precipitation and 11% occurs in Spring, which is the driest season. The annual rainfall of 18.1 inches in Boulder means that it is wetter than most places in Colorado.


January is the wettest month in Sisters with 1.6 inches of rain, and the driest month is August with 0.4 inches. The wettest season is Spring with 37% of yearly precipitation and 15% occurs in Autumn, which is the driest season. The annual rainfall of 11.4 inches in Sisters means that it is one of the driest places in Oregon.

May is the rainiest month in Boulder with 10.5 days of rain, and January is the driest month with only 4.7 rainy days. There are 88.0 rainy days annually in Boulder, which is rainier than most places in Colorado. The rainiest season is Autumn when it rains 31% of the time and the driest is Spring with only a 17% chance of a rainy day.

December is the rainiest month in Sisters with 9.1 days of rain, and August is the driest month with only 2.7 rainy days. There are 72.8 rainy days annually in Sisters, which is one of the least rainy places in Oregon. The rainiest season is Spring when it rains 34% of the time and the driest is Autumn with only a 15% chance of a rainy day.

An annual snowfall of 71.1 inches in Boulder means that it is snowier than most places in Colorado.

An annual snowfall of 16.1 inches in Sisters means that it is snowier than most places in Oregon.

March is the snowiest month in Boulder with 14.3 inches of snow, and 9 months of the year have significant snowfall.

December is the snowiest month in Sisters with 4.8 inches of snow, and 5 months of the year have significant snowfall.