Georgetown weather in September

In September, Georgetown sees average daytime highs of 88°F and overnight lows near 69°F, with 3.0 in of rain across 7.2 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 91°F in the first days to 85°F by the end. The sky is clear or mostly clear about 52% of the time in September, and the air most often feels muggy.

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

Daytime high
88°
4th warmest
Overnight low
69°
9th coldest
Rainfall
3.0 in
7.2 wet days
Daylight
12 h 12 min
6:20 AM – 6:31 PM
Cloud cover
43%
2nd clearest
Wind
7 mph
12th windiest
Solar energy
5.19 kWh/m²
Travel score
4.8
out of 10

Georgetown is city in and county seat of Williamson County, Texas, United States.

Density
491/km²
people per km²
Founded
1848

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 91°F in the first days to 85°F by the end.

A typical September day in Georgetown reaches about 88°F in the afternoon and slips back to 69°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 80°F and 95°F. Set against its neighbours, September runs about 6°F cooler than August and about 9°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19273
29273
39172
49172
59172
69172
79071
89071
99071
108971
118971
128970
138970
148870
158869
168869
178869
188769
198768
208768
218767
228767
238767
248666
258666
268666
278665
288565
298565
308564

How September really feels in Georgetown

Once humidity and wind are folded in, September averages 16 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
16
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.

Georgetown weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan60° / 40°2.46.610.25.2
Feb64° / 44°2.57.510.96.0
Mar71° / 51°3.19.111.86.8
Apr78° / 58°2.98.612.77.1
May84° / 66°4.611.313.55.4
Jun91° / 72°2.98.613.93.9
Jul94° / 75°1.65.713.83.0
Aug94° / 74°2.2613.13.0
Sep88° / 69°3.07.212.24.8
Oct79° / 59°3.77.311.27.2
Nov69° / 49°2.7710.57.0
Dec61° / 42°3.07.410.15.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 30%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17030
26931
36931
46832
56832
66733
76634
86634
96535
106535
116535
126535
136535
146535
156535
166634
176733
186832
196931
207030
217129
227228
237426
247525
257525
267624
277624
287723
297723
307723

Chance of precipitation in September

Any precipitation

Georgetown gets around 3.0 in of rain over 7.2 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 24% and peaks near 27% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
125
226
326
426
527
627
727
827
927
1027
1127
1227
1327
1427
1526
1626
1725
1824
1924
2023
2122
2221
2321
2420
2519
2619
2719
2818
2918
3019

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 33% of days. Sticky, muggy-or-worse air turns up on roughly 58% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
146214128
247214128
357214027
467214027
567213927
677213927
777203827
886203828
996193828
1096183828
11106183829
12107173729
13117163729
14127163629
15128163628
16138163528
17149163427
18159163327
191610163126
201711163025
211912172924
222012172823
232213172721
242314172620
252514172519
262615172417
272715182416
282815182315
292916182314
303016182313

Wind in September

Winds average 7 mph in September, the calmest month.

Across September, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
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 42 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 60 minutes over September. Sunrise moves from 6:11 AM to 6:28 AM, and sunset from 6:50 PM to 6:12 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.76:116:50
212.66:116:49
312.66:126:47
412.66:136:46
512.56:136:45
612.56:146:44
712.56:146:42
812.46:156:41
912.46:156:40
1012.46:166:38
1112.36:176:37
1212.36:176:36
1312.36:186:34
1412.26:186:33
1512.26:196:32
1612.26:206:31
1712.26:206:29
1812.16:216:28
1912.16:216:27
2012.16:226:25
2112.06:226:24
2212.06:236:23
2312.06:246:21
2411.96:246:20
2511.96:256:19
2611.96:256:17
2711.86:266:16
2811.86:276:15
2911.86:276:13
3011.76:286:12

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 2.71 kWh/m² to a high of 6.81 kWh/m² in July across the year — September's 5.19 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.7Bright
25.6Bright
35.6Bright
45.5Bright
55.5Bright
65.4Bright
75.4Bright
85.3Bright
95.3Bright
105.3Bright
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
284.9Bright
294.9Bright
304.9Bright
Planning a trip in September

Is September a good time to visit Georgetown?

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

4.8
Sightseeing
9th-best month of the year
7.2
Beach & pool
1st-best month of the year

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

What to pack for Georgetown in September

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

In September, Georgetown sees daytime highs around 88°F and nights near 69°F. Pack light clothes. Worth having: sun protection. About 7 days see rain.

light clothessun protection

UV index in Georgetown in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Georgetown peaks around July 24 at about 10 (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 highHighModerateJul 24UV 10Dec 20UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7High
Apr9Very high
May10Extreme
Jun10Extreme
Jul10Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov5Moderate
Dec4Moderate

Air quality in Georgetown 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 Georgetown is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (December, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1417 µg/m³Dec 127 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar9Good
Apr10Good
May14Moderate
Jun15Moderate
Jul18Moderate
Aug13Moderate
Sep10Good
Oct7Good
Nov7Good
Dec7Good
Location & terrain

Where is Georgetown?

Georgetown sits at 30.6°N, 97.7°W, 755 ft above sea level, in United States. The nearest listed city is Round Rock, 8.7 mi away.

Topography around Georgetown

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

Within 2 miles, the terrain around Georgetown has only modest variations in elevation — a maximum elevation change of 207 ft around an average of 755 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 522 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,463 ft.

The land around Georgetown is covered by trees (34%), grassland (32%) and artificial surfaces (30%) within 2 miles, grassland (40%) and trees (33%) within 10 miles, and grassland (44%) and trees (41%) within 50 miles.

2 miles
207 ft
10 miles
522 ft
50 miles
1,463 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Round Rock 8.7 mi · Brushy Creek 9.3 mi · Hutto 9.9 mi · Leander 11 mi · Cedar Park 12 mi · Pflugerville 14 mi · Jollyville 14 mi · Taylor 17 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 Georgetown (30.6327°, -97.6772°, elevation 755 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).