Semnan weather in October

In October, Semnan sees average daytime highs of 23°C and overnight lows near 12°C, with 5 mm of rain across 1.1 wet days and about 11.1 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 20°C by the end. The sky is clear or mostly clear about 76% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 36 min at the start of October to 10 h 36 min by month's end. Set against the rest of the year, October is Semnan's 5th-clearest and 8th-windiest month. For the whole year in context, see Semnan's year-round climate.

Daytime high
23°
6th warmest
Overnight low
12°
7th coldest
Rainfall
5 mm
1.1 wet days
Daylight
11 h 06 min
6:09 AM – 5:14 PM
Cloud cover
23%
5th clearest
Wind
9 km/h
8th windiest
Solar energy
4.58 kWh/m²
Travel score
8.8
out of 10

Semnan is city in Semnan Province, Iran.

Air quality
Elevated
PM10 48.4 µg/m³ · 2014
Founded
~240 CE

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 26°C in the first days to 20°C by the end.

A typical October day in Semnan reaches about 23°C in the afternoon and slips back to 12°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 27°C. Set against its neighbours, October runs about 7°C cooler than September and about 9°C warmer than November.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12715
22715
32615
42615
52614
62614
72514
82514
92514
102513
112413
122413
132413
142413
152313
162312
172312
182312
192312
202212
212211
222211
232211
242111
252111
262111
272010
282010
292010
302010
31199

How October really feels in Semnan

Once humidity and wind are folded in, October averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

October sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Semnan weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -0°123.21.79.91.6
Feb10° / 142.91.410.72.9
Mar16° / 183.90.911.75.7
Apr22° / 11°132.70.112.98.0
May28° / 17°51.3013.97.6
Jun33° / 21°10.3014.44.5
Jul36° / 24°10.3014.22.9
Aug35° / 23°10.3013.33.8
Sep30° / 18°20.5012.26.8
Oct23° / 12°51.1011.18.8
Nov15° / 1130.210.15.4
Dec / 103.10.99.62.3

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 76% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 10% of October, with mostly cloudy or overcast conditions the remaining 13%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1964
2946
3946
4946
5946
6928
7928
8928
9928
109010
119010
129010
139010
148812
158812
168812
178713
188614
198515
208515
218416
228317
238317
248218
258218
268119
278020
288020
297822
307822
317822

Chance of precipitation in October

Any precipitation

Semnan gets around 5 mm of rain over 1.1 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 4% and peaks near 8% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
12
22
32
42
52
62
72
83
93
103
113
123
133
143
153
163
173
183
194
204
214
224
235
245
256
266
276
287
297
308
318

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in October

Winds average 9 km/h in October.

Across October, daily wind ranges from about 8 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
288calm
298calm
308calm
318calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 36 min at the start of October to 10 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 60 minutes over October. Sunrise moves from 5:56 AM to 6:23 AM, and sunset from 5:35 PM to 4:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.65:565:35
211.65:575:33
311.65:585:32
411.55:595:30
511.55:595:29
611.56:005:28
711.46:015:26
811.46:025:25
911.36:035:23
1011.36:045:22
1111.36:055:21
1211.26:055:19
1311.26:065:18
1411.26:075:17
1511.16:085:15
1611.16:095:14
1711.06:105:13
1811.06:115:11
1911.06:125:10
2010.96:135:09
2110.96:145:08
2210.96:145:07
2310.86:155:05
2410.86:165:04
2510.86:175:03
2610.76:185:02
2710.76:195:01
2810.76:205:00
2910.66:214:59
3010.66:224:58
3110.66:234:57

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 4.58 kWh/m².

For context, solar energy here swings from a low near 2.8 kWh/m² to a high of 7.71 kWh/m² in June across the year — October's 4.58 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.1Bright
55.1Bright
65.0Bright
75.0Bright
84.9Bright
94.9Bright
104.9Bright
114.8Bright
124.8Bright
134.7Bright
144.7Bright
154.6Bright
164.6Bright
174.5Bright
184.5Bright
194.5Bright
204.4Bright
214.3Bright
224.3Bright
234.3Bright
244.2Bright
254.2Bright
264.1Bright
274.1Bright
284.0Bright
294.0Moderate
303.9Moderate
313.9Moderate
Planning a trip in October

Is October a good time to visit Semnan?

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

8.8
Sightseeing
1st-best month of the year
6.7
Beach & pool
6th-best month of the year

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

What to pack for Semnan in October

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

In October, Semnan sees daytime highs around 23°C and nights near 12°C. Worth packing: light clothes and sun protection.

light clothessun protection

UV index in Semnan in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October 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 Semnan peaks around July 19 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 19UV 11Jan 10UV 3
UV index (midday)Level
Jan3Moderate
Feb5High
Mar5Moderate
Apr8Very high
May10Very high
Jun10Very high
Jul11Extreme
Aug10Extreme
Sep8Very high
Oct6High
Nov4Moderate
Dec3Moderate

Air quality in Semnan in October

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where October falls, not just the annual average.

Air quality in Semnan is worst in December — around 46 µg/m³ PM2.5 (poor), about 2.1× the cleanest month (August, 22 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecPoorModeratePoorDec 1945 µg/m³Aug 1122 µg/m³
PM2.5 (µg/m³)Level
Jan43Poor
Feb41Poor
Mar38Poor
Apr40Poor
May34Moderate
Jun23Moderate
Jul23Moderate
Aug22Moderate
Sep28Moderate
Oct32Moderate
Nov39Poor
Dec46Poor
Location & terrain

Where is Semnan?

Semnan sits at 35.6°N, 53.4°E, 1,148 m above sea level, in Iran. The nearest listed city is Mahdishahr, 15 km away.

GarmsārĪstgāh-e Rāh Āhan-e GarmsārDāmghānQā’em ShahrSari

Topography around Semnan

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Semnan.

Within 3 km, the terrain around Semnan has only modest variations in elevation — a maximum elevation change of 144 m around an average of 1,149 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,254 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,375 m.

The land around Semnan is covered by artificial surfaces (59%) and bare terrain (20%) within 3 km, bare terrain (84%) within 16 km, and bare terrain (67%) and grassland (22%) within 80 km.

3 km
144 m
16 km
1,254 m
80 km
3,375 m
treesgrasslandcroplandartificial surfacesbare terrain
October weather nearby: Mahdishahr 15 km · Fīrūzkūh 60 km · Zīr Āb 77 km · Garmsār 103 km · Īstgāh-e Rāh Āhan-e Garmsār 105 km · Dāmghān 108 km · Qā’em Shahr 110 km · Sari 114 km

Iran travel facts

Travel advisory
Level 4
Do Not Travel
Power plugs
Type C / F
220 V · 50 Hz
Prices
≈ 352% of US
price level, 2025
GDP per capita
$3,924
2025
Happiness
5.2 / 10
World Happiness, 2025
Safe drinking water
94%
of population, 2024
Homicide rate
2.4
per 100k, 2014
Road deaths
21.5
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 492
Religion
Muslim 99%Christian 1%Baha'i 0%agnostic 0%

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 Semnan (35.5769°, 53.392°, elevation 1,148 m), 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).