Lebanon weather in September

In September, Lebanon sees average daytime highs of 77°F and overnight lows near 58°F, with 2.6 in of rain across 7.8 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 12th-wettest month of the year here.

Highs ease over the month, from about 81°F in the first days to 73°F by the end. The sky is clear or mostly clear about 43% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Lebanon's 1st-clearest and 10th-windiest month. For the whole year in context, see Lebanon's year-round climate.

Daytime high
77°
4th warmest
Overnight low
58°
9th coldest
Rainfall
2.6 in
7.8 wet days
Daylight
12 h 18 min
6:24 AM – 6:39 PM
Cloud cover
49%
1st clearest
Wind
6 mph
10th windiest
Solar energy
4.58 kWh/m²
Travel score
7.2
out of 10

Lebanon is city and the county seat of Warren County, Ohio, United States.

Density
617/km²
people per km²
Founded
1802

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 73°F by the end.

A typical September day in Lebanon 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 67°F and 87°F. Set against its neighbours, September runs about 6°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18264
28163
38163
48163
58162
68062
78062
88061
97961
107960
117960
127860
137859
147859
157758
167758
177758
187657
197657
207656
217556
227556
237455
247455
257455
267354
277354
287353
297253
307253

How September really feels in Lebanon

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.

Lebanon weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan38° / 24°3.310.24.49.50.0
Feb41° / 26°2.99.33.910.50.3
Mar51° / 34°4.111.42.111.72.5
Apr64° / 45°4.612.50.5135.2
May73° / 55°4.613.1014.16.2
Jun81° / 64°4.212.5014.75.9
Jul84° / 67°3.511014.55.4
Aug83° / 66°3.19.7013.56.0
Sep77° / 58°2.67.8012.37.2
Oct65° / 47°2.98.60.1116.0
Nov52° / 37°3.39.10.89.82.8
Dec42° / 29°3.69.939.30.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
35941
45941
56040
66040
76040
85941
95941
105941
115941
125842
135743
145743
155644
165644
175644
185545
195545
205644
215644
225743
235743
245743
255842
265842
275842
285842
295842
305842

Chance of precipitation in September

Any precipitation

Lebanon gets around 2.6 in of rain over 7.8 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 26% and peaks near 27% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
127
227
327
427
526
626
726
825
925
1025
1125
1225
1325
1426
1526
1626
1727
1827
1927
2027
2127
2227
2327
2427
2527
2626
2726
2826
2925
3024

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 42% of days. Sticky, muggy-or-worse air turns up on roughly 18% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
11725222610
21826212510
3202621249
4212720248
5232820237
6252819226
7262819215
8282819205
9302818194
10322818183
11332818183
12352818172
13372718162
14392717161
15412617151
16432617141
17452516131
18472416131
19492315121
20512315110
21532215100
22552114100
2357211390
2459201380
2561191280
2662191270
2763181270
2864181170
2966171160
3067161160

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 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
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 6:09 AM to 6:37 AM, and sunset from 7:04 PM to 6:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.96:097:04
212.96:107:02
312.86:117:00
412.86:126:59
512.76:136:57
612.76:146:56
712.66:156:54
812.66:166:52
912.66:176:51
1012.56:186:49
1112.56:196:47
1212.46:206:46
1312.46:216:44
1412.36:226:42
1512.36:236:40
1612.36:246:39
1712.26:246:37
1812.26:256:35
1912.16:266:34
2012.16:276:32
2112.06:286:30
2212.06:296:29
2311.96:306:27
2411.96:316:25
2511.96:326:24
2611.86:336:22
2711.86:346:20
2811.76:356:19
2911.76:366:17
3011.66:376:15

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 1.66 kWh/m² to a high of 6.2 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
25.1Bright
35.0Bright
45.0Bright
55.0Bright
64.9Bright
74.9Bright
84.9Bright
94.8Bright
104.8Bright
114.8Bright
124.7Bright
134.7Bright
144.7Bright
154.6Bright
164.6Bright
174.5Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.3Bright
234.3Bright
244.2Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.0Bright
304.0Bright
Planning a trip in September

Is September a good time to visit Lebanon?

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

7.2
Sightseeing
1st-best month of the year
6.4
Beach & pool
3rd-best month of the year

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

What to pack for Lebanon in September

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

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

light clothessun protection

UV index in Lebanon in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Lebanon peaks around June 21 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateJun 21UV 9Dec 22UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Lebanon 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 Lebanon is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1117 µg/m³Oct 238 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar12Good
Apr12Moderate
May15Moderate
Jun17Moderate
Jul17Moderate
Aug15Moderate
Sep12Good
Oct8Good
Nov8Good
Dec9Good
Location & terrain

Where is Lebanon?

Lebanon sits at 39.4°N, 84.2°W, 768 ft above sea level, in United States. The nearest listed city is Mason, 7.5 mi away.

Topography around Lebanon

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

Within 2 miles, the terrain around Lebanon has only modest variations in elevation — a maximum elevation change of 295 ft around an average of 814 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 551 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 919 ft.

The land around Lebanon is covered by trees (39%) and grassland (35%) within 2 miles, trees (42%), grassland (30%) and cropland (20%) within 10 miles, and cropland (42%) and trees (37%) within 50 miles.

2 miles
295 ft
10 miles
551 ft
50 miles
919 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Mason 7.5 mi · Springboro 8.1 mi · Middletown 12 mi · Centerville 14 mi · Miamisburg 15 mi · Kettering 17 mi · Forest Park 19 mi · Hamilton 19 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 Lebanon (39.4353°, -84.203°, elevation 768 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).