Seguin weather in September

In September, Seguin sees average daytime highs of 90°F and overnight lows near 71°F, with 2.8 in of rain across 8.8 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 93°F in the first days to 88°F by the end. The sky is clear or mostly clear about 50% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 36 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Seguin's 3rd-clearest and 12th-windiest month. For the whole year in context, see Seguin's year-round climate.

Daytime high
90°
4th warmest
Overnight low
71°
9th coldest
Rainfall
2.8 in
8.8 wet days
Daylight
12 h 12 min
6:21 AM – 6:31 PM
Cloud cover
46%
3rd clearest
Wind
7 mph
12th windiest
Solar energy
5.19 kWh/m²
Travel score
4.0
out of 10

Seguin is city in and county seat of Guadalupe County, Texas, United States.

Density
310/km²
people per km²
Founded
1838

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 93°F in the first days to 88°F by the end.

A typical September day in Seguin reaches about 90°F in the afternoon and slips back to 71°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 83°F and 97°F. Set against its neighbours, September runs about 6°F cooler than August and about 8°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19474
29374
39374
49374
59374
69273
79273
89273
99273
109173
119172
129172
139172
149072
159071
169071
179071
189071
198970
208970
218970
228969
238969
248969
258868
268868
278867
288867
298767
308767

How September really feels in Seguin

Once humidity and wind are folded in, September averages 24 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
24
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Seguin weather by month

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

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan63° / 43°2.47.110.36.0
Feb67° / 47°2.27.110.96.6
Mar73° / 54°2.88.611.87.1
Apr80° / 60°2.98.112.76.8
May87° / 68°4.110.113.54.9
Jun92° / 74°2.68.813.93.5
Jul95° / 75°1.86.813.72.7
Aug96° / 76°2.06.113.12.4
Sep90° / 71°2.88.812.24.0
Oct82° / 62°3.17.611.36.6
Nov72° / 52°2.77.110.57.2
Dec65° / 45°2.57.610.16.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% 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 33%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16733
26634
36634
46634
56436
66436
76436
86337
96436
106436
116337
126337
136436
146436
156337
166436
176436
186535
196733
206733
216832
226931
237129
247228
257228
267426
277525
287525
297525
307525

Chance of precipitation in September

Any precipitation

Seguin gets around 2.8 in of rain over 8.8 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 29% and peaks near 34% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
130
231
331
432
532
633
733
834
934
1034
1134
1234
1333
1433
1532
1632
1731
1830
1929
2028
2127
2226
2325
2425
2524
2623
2723
2822
2922
3022

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 41% of days. Sticky, muggy-or-worse air turns up on roughly 71% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
124933492
2351032482
3351033482
4351033482
5451033472
6451033472
7451033472
8551032472
9551032472
10551031472
11561031472
12661030472
13671029472
14671029472
15781028462
16781028452
17891127442
18891127422
1910101226412
2011101226392
2112111325382
2214111424361
2315111424341
2416111524321
2518111623301
2619111623291
2720111723271
2822111824251
2923111824241
3024101824231

Wind in September

Winds average 7 mph in September, the calmest month.

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
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 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 54 minutes over September. Sunrise moves from 6:13 AM to 6:29 AM, and sunset from 6:50 PM to 6:14 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.66:136:50
212.66:136:49
312.66:146:48
412.56:146:47
512.56:156:45
612.56:166:44
712.46:166:43
812.46:176:42
912.46:176:40
1012.46:186:39
1112.36:186:38
1212.36:196:37
1312.36:196:35
1412.26:206:34
1512.26:206:33
1612.26:216:31
1712.16:216:30
1812.16:226:29
1912.16:236:28
2012.16:236:26
2112.06:246:25
2212.06:246:24
2312.06:256:22
2411.96:256:21
2511.96:266:20
2611.96:266:19
2711.86:276:17
2811.86:286:16
2911.86:286:15
3011.76:296:14

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.19 kWh/m².

For context, solar energy here swings from a low near 2.69 kWh/m² to a high of 6.67 kWh/m² in July across the year — September's 5.19 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.6Bright
25.6Bright
35.5Bright
45.5Bright
55.5Bright
65.4Bright
75.4Bright
85.3Bright
95.3Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.1Bright
155.1Bright
165.1Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.0Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
294.9Bright
304.9Bright
Planning a trip in September

Is September a good time to visit Seguin?

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

4.0
Sightseeing
9th-best month of the year
6.7
Beach & pool
4th-best month of the year

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

What to pack for Seguin in September

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

In September, Seguin sees daytime highs around 90°F and nights near 71°F. Pack light clothes. Worth having: rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Seguin in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Seguin peaks around August 10 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 4 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateAug 10UV 11Dec 20UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7High
Apr10Very high
May10Extreme
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep9Very high
Oct6High
Nov5High
Dec4Moderate

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

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Oct 246 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar9Good
Apr10Good
May15Moderate
Jun15Moderate
Jul18Moderate
Aug12Good
Sep10Good
Oct6Good
Nov6Good
Dec7Good
Location & terrain

Where is Seguin?

Seguin sits at 29.6°N, 98.0°W, 522 ft above sea level, in United States. The nearest listed city is New Braunfels, 13 mi away.

Topography around Seguin

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

Within 2 miles, the terrain around Seguin has only modest variations in elevation — a maximum elevation change of 157 ft around an average of 528 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 410 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,775 ft.

The land around Seguin is covered by grassland (30%), trees (29%) and artificial surfaces (29%) within 2 miles, grassland (48%), trees (29%) and cropland (20%) within 10 miles, and grassland (48%) and trees (42%) within 50 miles.

2 miles
157 ft
10 miles
410 ft
50 miles
1,775 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: New Braunfels 13 mi · Cibolo 16 mi · Schertz 19 mi · Universal City 20 mi · Converse 21 mi · San Marcos 22 mi · Live Oak 22 mi · Canyon Lake 28 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 Seguin (29.5688°, -97.9647°, elevation 522 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).