Siloam Springs weather in September

In September, Siloam Springs sees average daytime highs of 82°F and overnight lows near 62°F, with 4.0 in of rain across 7.8 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 86°F in the first days to 77°F by the end. The sky is clear or mostly clear about 50% of the time in September, and the air most often feels dry.

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 Siloam Springs's 1st-clearest and 10th-windiest month. For the whole year in context, see Siloam Springs's year-round climate.

Daytime high
82°
4th warmest
Overnight low
62°
9th coldest
Rainfall
4.0 in
7.8 wet days
Daylight
12 h 12 min
6:06 AM – 6:19 PM
Cloud cover
43%
1st clearest
Wind
6 mph
10th windiest
Solar energy
4.91 kWh/m²
Travel score
6.7
out of 10

Siloam Springs is city in Arkansas, United States.

Density
557/km²
people per km²
Founded
1881

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 86°F in the first days to 77°F by the end.

A typical September day in Siloam Springs reaches about 82°F in the afternoon and slips back to 62°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 72°F and 90°F. Set against its neighbours, September runs about 7°F cooler than August and about 11°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18767
28667
38666
48666
58565
68565
78565
88464
98464
108364
118363
128363
138263
148262
158162
168162
178161
188061
198060
208060
217959
227959
237959
247858
257858
267857
277857
287756
297756
307756

How September really feels in Siloam Springs

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.

Siloam Springs 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 daysSnow daysDaylight (hours)Travel score
Jan46° / 29°2.67.11.79.81.5
Feb51° / 32°2.67.21.510.62.7
Mar60° / 40°4.110.21.111.74.8
Apr68° / 49°5.411012.96.2
May76° / 58°5.412.80.113.96.4
Jun84° / 67°4.211014.45.4
Jul89° / 71°3.39.7014.24.2
Aug89° / 69°2.99013.44.5
Sep82° / 62°4.07.8012.26.7
Oct70° / 50°4.08.2011.17.1
Nov58° / 40°3.380.310.14.7
Dec48° / 32°2.87.51.59.62.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 35%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16931
26832
36832
46733
56733
66634
76634
86535
96337
106337
116337
126337
136139
146139
156139
166139
176139
186238
196238
206337
216436
226535
236634
246733
256931
267030
277030
287129
297129
307129

Chance of precipitation in September

Any precipitation

Siloam Springs gets around 4.0 in of rain over 7.8 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 26% and peaks near 28% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
128
228
328
428
528
628
728
828
928
1028
1128
1228
1328
1428
1528
1628
1728
1828
1928
2027
2126
2225
2324
2423
2523
2622
2722
2821
2921
3021

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 28% of days. Sticky, muggy-or-worse air turns up on roughly 33% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1813244015
2913243915
31014243814
41215243613
51316243513
61416243412
71517243311
81717243210
9181724329
10191824318
11201824318
12211824307
13221823306
14241823296
15251823285
16261923284
17281823274
18301822263
19311822253
20331821253
21351821242
22381820222
23401819212
24421818202
25441818192
26461817181
27481717161
28511716151
29521716141
30531716131

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
266calm
276calm
286calm
297calm
307calm

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 5:54 AM to 6:17 AM, and sunset from 6:42 PM to 5:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.85:546:42
212.85:546:41
312.75:556:39
412.75:566:38
512.75:576:36
612.65:586:35
712.65:586:33
812.55:596:32
912.56:006:30
1012.56:016:29
1112.46:026:27
1212.46:026:25
1312.36:036:24
1412.36:046:22
1512.36:056:21
1612.26:066:19
1712.26:076:18
1812.16:076:16
1912.16:086:15
2012.16:096:13
2112.06:106:12
2212.06:116:10
2312.06:116:08
2411.96:126:07
2511.96:136:05
2611.86:146:04
2711.86:156:02
2811.86:166:01
2911.76:165:59
3011.76:175:58

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.91 kWh/m².

For context, solar energy here swings from a low near 2.23 kWh/m² to a high of 6.57 kWh/m² in July across the year — September's 4.91 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.5Bright
25.4Bright
35.4Bright
45.3Bright
55.3Bright
65.2Bright
75.2Bright
85.2Bright
95.1Bright
105.1Bright
115.0Bright
125.0Bright
134.9Bright
144.9Bright
154.9Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.7Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.5Bright
Planning a trip in September

Is September a good time to visit Siloam Springs?

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

6.7
Sightseeing
2nd-best month of the year
7.1
Beach & pool
1st-best month of the year

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

What to pack for Siloam Springs in September

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

In September, Siloam Springs sees daytime highs around 82°F and nights near 62°F. Pack light clothes. Worth having: sun protection. About 8 days see rain.

light clothessun protection

UV index in Siloam Springs in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Siloam Springs peaks around July 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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 12UV 10Dec 22UV 2
UV index (midday)Level
Jan3Moderate
Feb4Moderate
Mar6High
Apr8Very high
May8Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep8Very high
Oct5High
Nov4Moderate
Dec2Moderate

Air quality in Siloam Springs 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 Siloam Springs is worst in July — around 19 µg/m³ PM2.5 (moderate), about 3.0× the cleanest month (November, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodJul 1518 µg/m³Nov 236 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb9Good
Mar12Moderate
Apr11Good
May13Moderate
Jun16Moderate
Jul19Moderate
Aug15Moderate
Sep11Good
Oct7Good
Nov6Good
Dec6Good
Location & terrain

Where is Siloam Springs?

Siloam Springs sits at 36.2°N, 94.5°W, 1,132 ft above sea level, in United States. The nearest listed city is Bentonville, 22 mi away.

Topography around Siloam Springs

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

Within 2 miles, the terrain around Siloam Springs has only modest variations in elevation — a maximum elevation change of 207 ft around an average of 1,142 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 640 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,031 ft.

The land around Siloam Springs is covered by grassland (40%), trees (32%) and artificial surfaces (21%) within 2 miles, trees (47%) and grassland (43%) within 10 miles, and trees (60%) and grassland (33%) within 50 miles.

2 miles
207 ft
10 miles
640 ft
50 miles
2,031 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Bentonville 22 mi · Springdale 23 mi · Fayetteville 23 mi · Bella Vista 25 mi · Rogers 25 mi · Tahlequah 30 mi · Van Buren 53 mi · Muskogee 55 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 Siloam Springs (36.1881°, -94.5405°, elevation 1,132 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).