Bristol weather in September

In September, Bristol sees average daytime highs of 77°F and overnight lows near 58°F, with 3.0 in of rain across 8.3 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 81°F in the first days to 74°F by the end. The sky is clear or mostly clear about 39% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 12 h 48 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Bristol's 2nd-clearest and 10th-windiest month. For the whole year in context, see Bristol's year-round climate.

Daytime high
77°
4th warmest
Overnight low
58°
9th coldest
Rainfall
3.0 in
8.3 wet days
Daylight
12 h 12 min
6:16 AM – 6:30 PM
Cloud cover
52%
2nd clearest
Wind
4 mph
10th windiest
Solar energy
4.58 kWh/m²
Travel score
7.1
out of 10

Bristol is city in Sullivan County, Tennessee, United States.

Density
315/km²
people per km²
Founded
1856

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 81°F in the first days to 74°F by the end.

A typical September day in Bristol reaches about 77°F in the afternoon and slips back to 58°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 69°F and 86°F. Set against its neighbours, September runs about 5°F cooler than August and about 10°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18163
28162
38162
48162
58062
68061
78061
88061
98060
107960
117960
127960
137859
147859
157859
167858
177758
187758
197657
207657
217657
227656
237556
247556
257455
267455
277455
287454
297354
307353

How September really feels in Bristol

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Bristol weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan46° / 29°4.012.43.99.81.1
Feb49° / 32°3.711.63.510.61.9
Mar57° / 38°4.5132.311.73.9
Apr67° / 46°3.911.90.512.95.8
May73° / 54°3.612.8013.96.3
Jun80° / 62°3.213.2014.56.1
Jul83° / 66°3.313.5014.25.5
Aug82° / 65°2.810.4013.46.3
Sep77° / 58°3.08.3012.27.1
Oct67° / 47°2.88.90.211.16.5
Nov56° / 37°3.29.70.6104.0
Dec48° / 32°4.011.72.89.51.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 41%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
26040
36139
46139
56238
66238
76238
86238
96238
106139
116238
126238
136139
146139
156040
165941
175842
185743
195743
205644
215644
225644
235743
245743
255743
265743
275743
285842
295842
305842

Chance of precipitation in September

Any precipitation

Bristol gets around 3.0 in of rain over 8.3 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 27% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
127
227
327
426
526
626
726
825
925
1025
1125
1225
1325
1425
1525
1626
1727
1827
1928
2028
2129
2229
2329
2429
2528
2628
2727
2827
2927
3027

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the comfortable band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 16% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
110193833
211203732
312213631
413233529
514243427
615263326
717273224
818293122
919303021
1020312919
1122322818
1223332817
1324332716
1425342615
1526342614
1627352513
1728352413
1829352412
1930352311
2032342311
2133342310
223533229
233832229
244031218
254230217
264528207
274727196
285026186
295325175
305424175

Wind in September

Winds average 4 mph in September.

Across September, daily wind ranges from about 4 mph on the calmest days to 4 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 48 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 66 minutes over September. Sunrise moves from 6:04 AM to 6:28 AM, and sunset from 6:53 PM to 6:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.86:046:53
212.86:056:52
312.76:066:50
412.76:066:49
512.76:076:47
612.66:086:45
712.66:096:44
812.56:106:42
912.56:106:41
1012.56:116:39
1112.46:126:38
1212.46:136:36
1312.36:146:35
1412.36:156:33
1512.36:156:32
1612.26:166:30
1712.26:176:28
1812.16:186:27
1912.16:196:25
2012.16:196:24
2112.06:206:22
2212.06:216:21
2312.06:226:19
2411.96:236:17
2511.96:246:16
2611.86:256:14
2711.86:256:13
2811.86:266:11
2911.76:276:10
3011.76:286:08

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.58 kWh/m².

For context, solar energy here swings from a low near 2.09 kWh/m² to a high of 6.06 kWh/m² in June across the year — September's 4.58 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
74.9Bright
84.9Bright
94.9Bright
104.8Bright
114.8Bright
124.8Bright
134.7Bright
144.7Bright
154.6Bright
164.6Bright
174.5Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.3Bright
234.3Bright
244.3Bright
254.3Bright
264.2Bright
274.2Bright
284.2Bright
294.2Bright
304.2Bright
Planning a trip in September

Is September a good time to visit Bristol?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.1
Sightseeing
1st-best month of the year
6.5
Beach & pool
2nd-best month of the year

September is one of the better times to visit Bristol for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Bristol in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Bristol sees daytime highs around 77°F and nights near 58°F. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

UV index in Bristol in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bristol peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highVery highHighModerateJul 13UV 10Dec 20UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7High
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep7High
Oct5Moderate
Nov4Moderate
Dec2Moderate

Air quality in Bristol in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Bristol is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (December, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1517 µg/m³Dec 196 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb8Good
Mar9Good
Apr11Good
May13Moderate
Jun16Moderate
Jul18Moderate
Aug15Moderate
Sep11Good
Oct7Good
Nov7Good
Dec6Good
Location & terrain

Where is Bristol?

Bristol sits at 36.6°N, 82.2°W, 1,677 ft above sea level, in United States. The nearest listed city is Bristol, 0.0 mi away.

Topography around Bristol

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Bristol.

Within 2 miles, the terrain around Bristol has only modest variations in elevation — a maximum elevation change of 597 ft around an average of 1,772 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,411 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 5,486 ft.

The land around Bristol is covered by trees (56%), artificial surfaces (22%) and grassland (21%) within 2 miles, trees (60%) and grassland (33%) within 10 miles, and trees (80%) within 50 miles.

2 miles
597 ft
10 miles
1,411 ft
50 miles
5,486 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Bristol 0.0 mi · Kingsport 21 mi · Johnson City 22 mi · Boone 39 mi · Greeneville 47 mi · Lenoir 60 mi · Morganton 65 mi · Morristown 67 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Bristol (36.5951°, -82.1887°, elevation 1,677 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).