Mountain City, Tennessee Weather
Thunder quiets the land. Day 93 of summer. Read this microseason across nine climate regions →
Mountain City weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 10:21 AM EDT · Open-Meteo
- TodaySep 21Clear later15%—83°65°—
- TuesdaySep 22Overcast53%1.4″80°64°-3°
- WednesdaySep 23Drizzle51%—64°57°-16°
- ThursdaySep 24Drizzle50%0.03″61°53°-3°
- FridaySep 25Overcast——72°50°+11°
- SaturdaySep 26Overcast——73°49°+1°
- SundaySep 27Overcast——70°54°-3°
Air quality now AQI 37 · Good
AQI 37 (Good), driven by PM2.5. AQI projected to climb to 54 over the next 6 hours. PM2.5 at 9.4 µg/m³ (AQI 52) with a 0.94 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 7 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 42 now. With UV 4.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 22.
- Present
- AQI 42
- UV peak
- 4.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 22
PM × Wind × Precip
PM2.5 at 9.4 µg/m³ (AQI 52) with a 0.94 fine-to-coarse ratio and 2 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.94
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
September dries up ditches or breaks down bridges.
- Moonrise
- 4:50 PM
- Moonset
- 1:59 AM
- In sign
- ♑︎ Capricorn
Thunder quiets the land
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Mountain City at a glance
- Today vs. normal: Today averages 74°F (high 83°F, low 65°F), 11°F above the 63°F normal for Sep 21
- Last frost: April 27 (1991–2020 median, NOAA station 1 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
16-Day Forecast — Mountain City
- Mon83°65°15%
- Tue80°64°53%
- Wed64°57°51%
- Thu61°53°50%
- Fri72°50°5%
- Sat73°49°2%
- Sun70°54°2%
- Mon77°54°5%
- Tue76°56°10%
- Wed78°55°23%
- Thu78°58°22%
- Fri81°57°26%
- Sat75°57°18%
- Sun66°63°29%
- Mon65°44°35%
- Tue63°37°36%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 14) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
SPC Convective Outlook
Storm Prediction Center — Mountain City
SPC has placed Mountain City in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook.
Sun & seasons in Mountain City
Mountain City sits in Johnson County, where the year’s longest day runs 14h 39m of daylight and its shortest just 9h 40m — a swing of +4h 59m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Nashville, the state’s largest city, lies about 278 miles to the W. The nearest town Mountain City tracks is Johnson City, roughly 33 miles to the WSW.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| April | lettuce, peas, spinach, radishes | radishes |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| July | tomatoes, peppers, beans, squash, fall brassicas, carrots | lettuce, peas, spinach, tomatoes, peppers, beans, summer squash, garlic |
| August | — | tomatoes, peppers, beans, summer squash, winter squash, garlic |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | — | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
Mountain City's warmest month is July (~71°F mean) and its coldest is January (~34°F). Rainfall peaks in May (5.2 inches) and bottoms out in October (2.8 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 34° | 3.7″ | 9 |
| February | 37° | 3.4″ | 9 |
| March | 44° | 4.1″ | 10 |
| April | 53° | 4.3″ | 10 |
| May | 61° | 5.2″ | 12 |
| June | 68° | 4.5″ | 12 |
| July | 71° | 5.0″ | 12 |
| August | 70° | 4.2″ | 10 |
| September | 65° | 3.3″ | 8 |
| October | 55° | 2.8″ | 7 |
| November | 45° | 2.9″ | 7 |
| December | 38° | 3.9″ | 9 |
Regional context
Similar climates Butler, TN, Hunter, TN, Bristol, TN
In Mountain City, NOAA NCEI 1991-2020 normals put January near 34°F and July near 71°F — a 37°F seasonal arc — with about 47.2 inches of precipitation over 114 rainy or snowy days.
Rainfall in Mountain City splits evenly between the seasons: May tops out at 5.2 inches over 11.8 rainy days, and October logs 2.8 inches across 6.8 — neither half of Mountain City's year dominates. It is a balanced pattern Mountain City shares with places like Butler, TN, Hunter, TN and Bristol, TN.
Once Mountain City passes April 27, freezes fade and Mountain City's beds take peas, lettuce, spinach, and radishes. Heat-demanding starts go out a fortnight on in Mountain City, after the soil warms and cold snaps clear. By October 14, frost is back in Mountain City — protect or harvest anything tender. That date is a median: Mountain City freezes sooner in half of years.
Similar climates: Butler, TN, Hunter, TN, Bristol, TN, Biltmore, TN, Hampton, TN.
Frequently asked
- When does it freeze in Mountain City?
- Mountain City's last spring frost lands near April 27, and in Mountain City the first fall frost follows around October 14.
- What is the rainy season in Mountain City?
- May is the wettest month in Mountain City, about 5.2 inches on average; the year totals roughly 47 inches.
- What is the warmest month in Mountain City?
- July is Mountain City's warmest month, averaging about 71°F.
- What is the coldest month in Mountain City?
- Mountain City bottoms out in January, with a mean near 34°F.
- When can I start a vegetable garden in Mountain City?
- Mountain City's last frost (April 27) cues hardy greens; in Mountain City, hold heat-lovers two weeks past.
- How many rainy days does Mountain City get?
- Expect roughly 114 wet days a year in Mountain City.
- What hardiness zone is Mountain City?
- Mountain City's hardiness zone tracks its winter low; with January near 34°F, check the USDA ZIP map for the exact zone.
- What is the 10-day forecast for Mountain City?
- Mountain City's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Mountain City?
- See this week's day-by-day rain chances for Mountain City in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Mountain City?
- Current conditions for Mountain City and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Mountain City forecast updated?
- The Mountain City forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Mountain City?
- Today's sunrise and sunset times for Mountain City are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Mountain City?
- The next few days in Mountain City's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Mountain City sits at 36.5°N; its climate zone is humid subtropical (Köppen approximation).
ZIP codes in Mountain City
- 37683