Chattanooga, Tennessee, has hot and humid summers and short, chilly winters. Temperatures change noticeably through the year, with typical temperatures ranging from about 33°F to 89°F. Extreme temperatures below 19°F or above 96°F are uncommon based on the climate data used for this report.
For people planning outdoor activities or a trip to Chattanooga, weather conditions are generally most favorable from mid-May to mid-June and again from mid-August to early October. The third week of September has the highest tourism score in the source data.
Chattanooga Weather by Month
Chattanooga’s temperatures follow a typical four-season pattern. January is the coldest part of the year, while July is the hottest. Temperatures rise steadily through spring before reaching their summer peak and then gradually fall during autumn.
| Month | Average High | Average Low |
|---|---|---|
| January | 50°F | 33°F |
| February | 55°F | 36°F |
| March | 64°F | 43°F |
| April | 72°F | 51°F |
| May | 79°F | 59°F |
| June | 86°F | 67°F |
| July | 89°F | 70°F |
| August | 88°F | 70°F |
| September | 82°F | 63°F |
| October | 72°F | 51°F |
| November | 62°F | 42°F |
| December | 53°F | 36°F |
The monthly figures show how quickly Chattanooga warms during spring. Average highs climb from 64°F in March to 72°F in April and 79°F in May. Summer is hottest in July, when the average high reaches 89°F and the average low is around 70°F.
January is the coolest month, with an average high of 50°F and a low of 33°F. By April, temperatures are considerably milder, with average highs around 72°F and lows around 51°F.
Summer in Chattanooga
Summer is the warmest and most humid period of the year. The hot season typically lasts about 3.8 months, from May 25 through September 19, with average daily highs above 81°F. July is the hottest month, averaging 89°F during the day and 70°F at night.
Humidity also becomes much more noticeable during summer. July has an average of 25.2 muggy days, compared with virtually none during January and February.
Winter in Chattanooga
Winter is much cooler, although prolonged freezing conditions are not typical. The cool season generally lasts about 2.9 months, from November 28 to February 25, with average daily highs below 58°F.
January is the coldest month, with an average high of 50°F and an average low of 33°F.
Rainfall in Chattanooga
Rain occurs throughout the year in Chattanooga, although the amount varies from month to month. December is the wettest month, with an average rainfall of 4.7 inches, while August is the driest, averaging 2.8 inches.
| Month | Average Rainfall |
|---|---|
| January | 4.2 inches |
| February | 4.4 inches |
| March | 4.6 inches |
| April | 4.2 inches |
| May | 3.6 inches |
| June | 3.4 inches |
| July | 3.3 inches |
| August | 2.8 inches |
| September | 3.4 inches |
| October | 3.1 inches |
| November | 4.2 inches |
| December | 4.7 inches |
Chattanooga’s wetter season runs approximately from March 20 to August 23. July has the most wet days, averaging 12.9 days with at least 0.04 inches of precipitation. October has the fewest, at about 6.9 days.
Rain is by far the most common form of precipitation. July averages nearly 12.9 days of rain, while snowfall and mixed precipitation are concentrated primarily in the winter months.
Snowfall in Chattanooga
Snow is relatively limited and strongly seasonal in Chattanooga. The period with the greatest likelihood of accumulating snow runs from roughly January 1 to February 9.
January is the snowiest month, with an average snowfall of about 1.4 inches. February averages 0.8 inches, while March averages just 0.2 inches. From April through October, average monthly snowfall is essentially zero.
| Month | Average Snowfall |
|---|---|
| January | 1.4 inches |
| February | 0.8 inches |
| March | 0.2 inches |
| April | 0.0 inches |
| May | 0.0 inches |
| June | 0.0 inches |
| July | 0.0 inches |
| August | 0.0 inches |
| September | 0.0 inches |
| October | 0.0 inches |
| November | 0.0 inches |
| December | 0.5 inches |
The source estimates that Chattanooga has about 11 months of the year without significant snowfall, with the least snow occurring around late July.
Cloud Cover
Cloud cover changes considerably throughout the year. Chattanooga’s clearer period generally begins around June 13 and lasts until about November 20.
September is the clearest month, with skies classified as clear, mostly clear or partly cloudy about 65% of the time. January is the cloudiest month, with overcast or mostly cloudy conditions about 54% of the time.
| Month | Clearer Conditions | Cloudier Conditions |
|---|---|---|
| January | 46% | 54% |
| February | 47% | 53% |
| March | 50% | 50% |
| April | 55% | 45% |
| May | 55% | 45% |
| June | 56% | 44% |
| July | 59% | 41% |
| August | 65% | 35% |
| September | 65% | 35% |
| October | 65% | 35% |
| November | 56% | 44% |
| December | 47% | 53% |
Humidity
Humidity is one of the defining features of Chattanooga’s summer climate. The muggy period generally runs from May 20 to September 28, when muggy, oppressive or miserable conditions occur at least 21% of the time.
July is the most humid month in terms of perceived conditions, with about 25.2 muggy days. February has the fewest, with an average of 0.0 muggy days.
| Month | Average Muggy Days |
|---|---|
| January | 0.0 |
| February | 0.0 |
| March | 0.0 |
| April | 0.5 |
| May | 6.0 |
| June | 17.3 |
| July | 25.2 |
| August | 23.0 |
| September | 11.5 |
| October | 2.1 |
| November | 0.2 |
| December | 0.0 |
Wind in Chattanooga
Wind speeds vary only moderately during the year. The windier period generally runs from October 27 to May 12, when average hourly wind speeds are above 4.4 mph.
March is the windiest month, with an average hourly wind speed of 5.5 mph. Conditions become calmer from May through October, with August being the calmest month at about 3.3 mph.
The predominant wind direction also changes during the year. Northerly winds are more common during parts of winter, while southerly winds dominate much of the year. Westerly winds are most common during part of July.
Daylight in Chattanooga
Daylight hours vary substantially between winter and summer. The shortest day of the year is around December 21, with approximately 9 hours and 48 minutes of daylight. The longest day is around June 21, when Chattanooga receives about 14 hours and 31 minutes of daylight.
Average daylight by month is approximately:
| Month | Average Daylight |
|---|---|
| January | 10.1 hours |
| February | 11.0 hours |
| March | 12.0 hours |
| April | 13.1 hours |
| May | 14.0 hours |
| June | 14.5 hours |
| July | 14.2 hours |
| August | 13.4 hours |
| September | 12.3 hours |
| October | 11.2 hours |
| November | 10.3 hours |
| December | 9.8 hours |
Growing Season
Using a definition based on the longest continuous period of non-freezing temperatures, Chattanooga’s growing season typically lasts about 7.5 months, or 228 days.
It generally runs from around March 26 to November 9. The source notes that the growing season can begin as early as March 5 or as late as April 15, while its end can range from October 22 to November 28.
When Is the Best Time to Visit Chattanooga?
The best time to visit depends on the type of weather you prefer.
For general outdoor sightseeing and activities, the source identifies mid-May to mid-June and mid-August to early October as the most favorable periods. The highest tourism score occurs around the third week of September.
For hotter weather and pool or water-based activities, the preferred period extends from mid-June to early September, with the highest beach/pool score around the second week of August.
In practical terms, spring and early fall offer a balance between warm temperatures and lower humidity, while summer is better suited to travelers who enjoy hotter, more humid conditions.
Chattanooga Climate at a Glance
- Typical annual temperature range: 33°F to 89°F
- Hottest month: July
- Average July high: 89°F
- Average July low: 70°F
- Coldest month: January
- Average January high: 50°F
- Average January low: 33°F
- Wettest month: December, with about 4.7 inches of rain
- Driest month: August, with about 2.8 inches of rain
- Snowiest month: January, with about 1.4 inches
- Windiest month: March, with an average wind speed of 5.5 mph
- Calmest month: August, at about 3.3 mph
- Clearest months: August through October, with September among the clearest
- Most humid month: July
- Typical growing season: About 228 days
How the Weather Data Was Compiled
The climate information in the source is based on a statistical analysis of historical hourly weather reports and model reconstructions covering January 1, 1980 through December 31, 2016.
Temperature and dew-point estimates use information from five nearby weather stations. The individual station records are adjusted for elevation differences and changes represented in MERRA-2 reanalysis data, with the final Chattanooga estimate calculated using a distance-weighted average.
The tourism and outdoor activity scores use hourly conditions between 8 a.m. and 9 p.m., combining perceived temperature, cloud cover and precipitation into composite scores.
Source
WeatherSpark, Average Weather in Chattanooga, Tennessee, United States, Year Round.