Jacksonville weather in September

In September, Jacksonville sees average daytime highs of 82°F and overnight lows near 66°F, with 6.5 in of rain across 13.3 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 3rd-wettest month of the year here.

Highs ease over the month, from about 84°F in the first days to 79°F by the end. The sky is clear or mostly clear about 32% of the time in September, and the air most often feels oppressive.

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 Jacksonville's 9th-clearest and 9th-windiest month. For the whole year in context, see Jacksonville's year-round climate.

Daytime high
82°
4th warmest
Overnight low
66°
9th coldest
Rainfall
6.5 in
13.3 wet days
Daylight
12 h 12 min
5:58 AM – 6:10 PM
Cloud cover
59%
9th clearest
Wind
6 mph
9th windiest
Solar energy
4.33 kWh/m²
Travel score
5.7
out of 10

Jacksonville is city in Onslow County, North Carolina, United States.

Density
513/km²
people per km²
Founded
1757

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 84°F in the first days to 79°F by the end.

A typical September day in Jacksonville reaches about 82°F in the afternoon and slips back to 66°F overnight — a 15°F spread between the day's warmth and the night's chill. On most days the high lands between 75°F and 88°F. Set against its neighbours, September runs about 4°F cooler than August and about 8°F warmer than October.

50°60°70°80°90°151015202530
Avg high (°F)Avg low (°F)
18570
28469
38469
48469
58469
68469
78368
88368
98368
108368
118367
128367
138267
148267
158267
168266
178266
188166
198165
208165
218165
228065
238064
248064
258064
267964
277963
287963
297962
307862

How September really feels in Jacksonville

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.

Jacksonville weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan55° / 37°3.690.69.93.7
Feb58° / 39°3.38.90.510.74.4
Mar64° / 44°3.69.40.111.76.0
Apr73° / 53°3.38.8012.87.0
May79° / 61°4.111013.86.5
Jun85° / 69°5.615.5014.34.5
Jul87° / 73°6.719.8014.13.6
Aug86° / 72°6.817.3013.34.1
Sep82° / 66°6.513.3012.25.7
Oct74° / 56°4.08.5011.17.1
Nov65° / 45°3.67.9010.26.4
Dec58° / 40°3.69.40.19.74.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 51%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14852
24852
34852
44852
54852
64852
74951
84951
94951
104951
115050
125050
135050
145050
154951
165050
175050
185050
194852
204852
214951
224852
234852
244951
254951
265050
275050
285050
295149
305149

Chance of precipitation in September

Any precipitation

Jacksonville gets around 6.5 in of rain over 13.3 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 43% and peaks near 49% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
149
249
348
448
547
646
746
845
945
1044
1143
1243
1342
1442
1542
1642
1742
1842
1942
2042
2142
2242
2342
2442
2541
2640
2740
2839
2938
3038

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 65% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1131225518
2141325508
3141425498
4151425477
5251526467
6261526456
7261627436
8271627425
9371728405
10381728395
11491729374
12491730364
134101830354
145101831333
155111831323
166111832313
176111832303
187111932292
198111931292
209111931282
219122030272
2211122029272
2312122029261
2413122128251
2514122127241
2615132226241
2717132225231
2818132324221
2919132323211
3020132322201

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:46 AM to 6:08 AM, and sunset from 6:32 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:466:32
212.75:476:31
312.75:486:30
412.75:496:28
512.65:496:27
612.65:506:25
712.55:516:24
812.55:526:22
912.55:526:21
1012.45:536:19
1112.45:546:18
1212.45:556:16
1312.35:556:15
1412.35:566:13
1512.35:576:12
1612.25:586:10
1712.25:586:09
1812.15:596:07
1912.16:006:06
2012.16:016:05
2112.06:016:03
2212.06:026:02
2312.06:036:00
2411.96:045:59
2511.96:045:57
2611.86:055:56
2711.86:065:54
2811.86:075:53
2911.76:075:51
3011.76:085:50

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.33 kWh/m².

For context, solar energy here swings from a low near 2.38 kWh/m² to a high of 6.04 kWh/m² in May across the year — September's 4.33 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.6Bright
84.6Bright
94.5Bright
104.5Bright
114.5Bright
124.5Bright
134.4Bright
144.4Bright
154.4Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.2Bright
214.2Bright
224.2Bright
234.1Bright
244.1Bright
254.1Bright
264.1Bright
274.1Bright
284.0Bright
294.0Bright
304.0Bright
Planning a trip in September

Hazard calendar for Jacksonville

In seasonPeak

In September, Jacksonville sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Jacksonville sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Jacksonville?

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

5.7
Sightseeing
6th-best month of the year
6.2
Beach & pool
2nd-best month of the year

September is a reasonable time to visit Jacksonville for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Jacksonville in September

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

In September, Jacksonville sees daytime highs around 82°F and nights near 66°F. Pack light clothes. Worth having: rain gear. About 13 days see rain.

light clothesrain gear

Sea temperature near Jacksonville in September

The nearest coast averages about 80°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 19 mi away) is warmest in August at about 82°F and coldest in February near 58°F.

It's comfortable for a long swim from May 6 to Nov 13 — about 6.3 months when the water holds above 68°F.

60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan60Cool
Feb58Bracing
Mar60Cool
Apr64Cool
May70Refreshing
Jun77Warm
Jul81Warm
Aug82Warm
Sep80Warm
Oct74Refreshing
Nov67Cool
Dec63Cool

UV index in Jacksonville 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 Jacksonville peaks around July 14 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highModerateJul 14UV 9Dec 19UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr7Very high
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep7Very high
Oct5Moderate
Nov4Moderate
Dec2Moderate

Air quality in Jacksonville 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 Jacksonville is worst in March — around 21 µg/m³ PM2.5 (moderate), about 3.3× the cleanest month (December, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMar 1720 µg/m³Dec 136 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb13Moderate
Mar21Moderate
Apr14Moderate
May13Moderate
Jun17Moderate
Jul17Moderate
Aug14Moderate
Sep10Good
Oct8Good
Nov7Good
Dec6Good
Location & terrain

Where is Jacksonville?

Jacksonville sits at 34.8°N, 77.4°W, 13 ft above sea level, in United States. The nearest listed city is Havelock, 31 mi away.

Topography around Jacksonville

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

Within 2 miles, the terrain around Jacksonville has only modest variations in elevation — a maximum elevation change of 85 ft around an average of 26 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 246 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 289 ft.

The land around Jacksonville is covered by trees (55%) within 2 miles, trees (69%) within 10 miles, and trees (56%) and water (25%) within 50 miles.

2 miles
85 ft
10 miles
246 ft
50 miles
289 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Havelock 31 mi · New Bern 33 mi · Kinston 36 mi · Wilmington 47 mi · Leland 49 mi · Goldsboro 54 mi · Greenville 60 mi · Wilson 72 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 Jacksonville (34.754°, -77.4302°, elevation 13 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).