2025 Compare Climate & Weather:
Montgomery, IL vs Chantilly, VA

Highlights

On average, there are 197 sunny days per year in Chantilly. Montgomery averages 189 sunny days per year. The US average is 205 sunny days.

Chantilly, Virginia gets 42.9 inches of rain, on average, per year. Montgomery, Illinois gets 37.7 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Chantilly averages 21.5 inches of snow per year. Montgomery averages 28.2 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Chantilly, Virginia
Summer High: the July high is around 85.8 degrees
Winter Low: the January low is 23.5
Rain: averages 42.9 inches of rain a year
Snow: averages 21.5 inches of snow a year

Montgomery, Illinois
Summer High: the July high is around 83.7 degrees
Winter Low: the January low is 14.4
Rain: averages 37.7 inches of rain a year
Snow: averages 28.2 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Chantilly is 7.3 (10=best), which means it is about average compared to other places in Virginia.

The annual BestPlaces Comfort Index for Montgomery is 6.8 (10=best), which means it is less comfortable than most places in Illinois.

Today's Weather - Montgomery, IL

71°F

Today's Weather - Chantilly, VA

78°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Montgomery / Chantilly

July is the hottest month for Montgomery with an average high temperature of 83.7°, which ranks it as cooler than most places in Illinois. In Montgomery, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Montgomery are June, September and August.

July is the hottest month for Chantilly with an average high temperature of 85.8°, which ranks it as cooler than most places in Virginia. In Chantilly, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Chantilly are September, June and May.

January has the coldest nighttime temperatures for Montgomery with an average of 14.4°. This is colder than most places in Illinois.

January has the coldest nighttime temperatures for Chantilly with an average of 23.5°. This is colder than most places in Virginia.

In Montgomery, there are 9.8 days annually when the high temperature is over 90°, which is one of the coolest places in Illinois.

In Chantilly, there are 19.0 days annually when the high temperature is over 90°, which is cooler than most places in Virginia.

In Montgomery, there are 134.6 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Illinois.

In Chantilly, there are 103.9 days annually when the nighttime low temperature falls below freezing, which is about average compared to other places in Virginia.

In Montgomery, there are 9.1 days annually when the nighttime low temperature falls below zero°, which is colder than most places in Illinois.

In Chantilly, there are 0.6 days annually when the nighttime low temperature falls below zero°, which is colder than most places in Virginia.

August is the wettest month in Montgomery with 4.2 inches of rain, and the driest month is January with 1.6 inches. The wettest season is Autumn with 33% of yearly precipitation and 14% occurs in Spring, which is the driest season. The annual rainfall of 37.7 inches in Montgomery means that it is drier than most places in Illinois.


May is the wettest month in Chantilly with 4.6 inches of rain, and the driest month is February with 2.8 inches. The wettest season is Summer with 28% of yearly precipitation and 21% occurs in Spring, which is the driest season. The annual rainfall of 42.9 inches in Chantilly means that it is drier than most places in Virginia.

May is the rainiest month in Montgomery with 11.9 days of rain, and September is the driest month with only 8.0 rainy days. There are 119.8 rainy days annually in Montgomery, which is rainier than most places in Illinois. The rainiest season is Summer when it rains 28% of the time and the driest is Winter with only a 22% chance of a rainy day.

May is the rainiest month in Chantilly with 12.2 days of rain, and October is the driest month with only 8.1 rainy days. There are 119.5 rainy days annually in Chantilly, which is rainier than most places in Virginia. The rainiest season is Summer when it rains 28% of the time and the driest is Winter with only a 22% chance of a rainy day.

An annual snowfall of 28.2 inches in Montgomery means that it is snowier than most places in Illinois.

An annual snowfall of 21.5 inches in Chantilly means that it is one of the snowiest places in Virginia.

January is the snowiest month in Montgomery with 8.7 inches of snow, and 6 months of the year have significant snowfall.

February is the snowiest month in Chantilly with 7.8 inches of snow, and 5 months of the year have significant snowfall.