Semnan weather in December

In December, Semnan sees average daytime highs of 9°C and overnight lows near 1°C, with 10 mm of precipitation across 3.1 wet days and about 9.6 hours of daylight. It is the 11th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 10°C in the first days to 8°C by the end. The sky is clear or mostly clear about 57% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 48 min at the start of December to 9 h 36 min by month's end. Set against the rest of the year, December is Semnan's 10th-clearest and 12th-windiest month. For the whole year in context, see Semnan's year-round climate.

Daytime high: 9°; 11th warmest
Overnight low: 1°; 2nd coldest
Precipitation: 10 mm; 3.1 wet days
Daylight: 9 h 36 min; 7:04 AM – 4:41 PM
Cloud cover: 38%; 10th clearest
Wind: 7 km/h; 12th windiest
Solar energy: 2.8 kWh/m²
Travel score: 2.3; 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.

← November Semnan year-round climate January →Best places to visit in December

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 10°C in the first days to 8°C by the end.

A typical December day in Semnan reaches about 9°C in the afternoon and slips back to 1°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 5°C and 13°C. Set against its neighbours, December runs about 5°C cooler than November and about 1°C warmer than January.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°C)	11	10	10	10	10	10	10	10	10	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	8	8
Avg low (°C)	3	3	3	2	2	2	2	2	2	2	2	2	1	1	1	1	1	1	1	1	1	1	1	1	1	0	0	0	0	0	0

	Avg high (°C)	Avg low (°C)
1	11	3
2	10	3
3	10	3
4	10	2
5	10	2
6	10	2
7	10	2
8	10	2
9	10	2
10	9	2
11	9	2
12	9	2
13	9	1
14	9	1
15	9	1
16	9	1
17	9	1
18	9	1
19	9	1
20	9	1
21	9	1
22	9	1
23	9	1
24	9	1
25	9	1
26	9	0
27	9	0
28	9	0
29	9	0
30	8	0
31	8	0

How December really feels in Semnan

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 24 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Semnan weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 6th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	8° / -0°	12	3.2	1.7	9.9	1.6
Feb	10° / 1°	14	2.9	1.4	10.7	2.9
Mar	16° / 6°	18	3.9	0.9	11.7	5.7
Apr	22° / 11°	13	2.7	0.1	12.9	8.0
May	28° / 17°	5	1.3	0	13.9	7.6
Jun	33° / 21°	1	0.3	0	14.4	4.5
Jul	36° / 24°	1	0.3	0	14.2	2.9
Aug	35° / 23°	1	0.3	0	13.3	3.8
Sep	30° / 18°	2	0.5	0	12.2	6.8
Oct	23° / 12°	5	1.1	0	11.1	8.8
Nov	15° / 6°	11	3	0.2	10.1	5.4
Dec	9° / 1°	10	3.1	0.9	9.6	2.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 57% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 29%. Skies tend to open up as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	67	67	67	67	67	67	67	67	68	68	69	69	70	71	71	72	72	72	73	74	74	75	75	75	76	76	76	76	76	74	74
Cloudier (%)	33	33	33	33	33	33	33	33	32	32	31	31	30	29	29	28	28	28	27	26	26	25	25	25	24	24	24	24	24	26	26

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	67	33
4	67	33
5	67	33
6	67	33
7	67	33
8	67	33
9	68	32
10	68	32
11	69	31
12	69	31
13	70	30
14	71	29
15	71	29
16	72	28
17	72	28
18	72	28
19	73	27
20	74	26
21	74	26
22	75	25
23	75	25
24	75	25
25	76	24
26	76	24
27	76	24
28	76	24
29	76	24
30	74	26
31	74	26

Chance of precipitation in December

Any precipitationSnow

Semnan gets around 10 mm of rain and snow over 3.1 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 10% and peaks near 11% on the wettest days, and about 1 day brings snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	11	11	11	11	11	11	11	11	11	11	11	10	10	10	10	10	10	10	10	10	9	9	9	9	9	9	9	9	9	9	9
Snow chance (%)	2	2	2	2	2	2	2	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3	3

	Rain chance (%)	Snow chance (%)
1	11	2
2	11	2
3	11	2
4	11	2
5	11	2
6	11	2
7	11	2
8	11	3
9	11	3
10	11	3
11	11	3
12	10	3
13	10	3
14	10	3
15	10	3
16	10	3
17	10	3
18	10	3
19	10	3
20	10	3
21	9	3
22	9	3
23	9	3
24	9	3
25	9	3
26	9	3
27	9	3
28	9	3
29	9	3
30	9	3
31	9	3

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

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

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in December

Winds average 7 km/h in December, the calmest month.

Across December, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (km/h)	7	7	7	7	7	7	7	7	7	7	7	7	7	6	6	6	6	6	6	6	6	7	7	7	7	7	7	7	7	7	7
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	7	calm
2	7	calm
3	7	calm
4	7	calm
5	7	calm
6	7	calm
7	7	calm
8	7	calm
9	7	calm
10	7	calm
11	7	calm
12	7	calm
13	7	calm
14	6	calm
15	6	calm
16	6	calm
17	6	calm
18	6	calm
19	6	calm
20	6	calm
21	6	calm
22	7	calm
23	7	calm
24	7	calm
25	7	calm
26	7	calm
27	7	calm
28	7	calm
29	7	calm
30	7	calm
31	7	calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 48 min at the start of December to 9 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 6:53 AM to 7:11 AM, and sunset from 4:39 PM to 4:48 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	9.8	9.8	9.7	9.7	9.7	9.7	9.7	9.7	9.7	9.7	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6	9.6
Sunrise (AM)	6:53	6:54	6:55	6:56	6:56	6:57	6:58	6:59	7:00	7:00	7:01	7:02	7:02	7:03	7:04	7:04	7:05	7:06	7:06	7:07	7:07	7:08	7:08	7:09	7:09	7:09	7:10	7:10	7:10	7:11	7:11
Sunset (PM)	4:39	4:39	4:39	4:39	4:39	4:39	4:39	4:39	4:39	4:39	4:40	4:40	4:40	4:40	4:40	4:41	4:41	4:41	4:42	4:42	4:43	4:43	4:44	4:44	4:45	4:45	4:46	4:46	4:47	4:48	4:48

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	9.8	6:53	4:39
2	9.8	6:54	4:39
3	9.7	6:55	4:39
4	9.7	6:56	4:39
5	9.7	6:56	4:39
6	9.7	6:57	4:39
7	9.7	6:58	4:39
8	9.7	6:59	4:39
9	9.7	7:00	4:39
10	9.7	7:00	4:39
11	9.6	7:01	4:40
12	9.6	7:02	4:40
13	9.6	7:02	4:40
14	9.6	7:03	4:40
15	9.6	7:04	4:40
16	9.6	7:04	4:41
17	9.6	7:05	4:41
18	9.6	7:06	4:41
19	9.6	7:06	4:42
20	9.6	7:07	4:42
21	9.6	7:07	4:43
22	9.6	7:08	4:43
23	9.6	7:08	4:44
24	9.6	7:09	4:44
25	9.6	7:09	4:45
26	9.6	7:09	4:45
27	9.6	7:10	4:46
28	9.6	7:10	4:46
29	9.6	7:10	4:47
30	9.6	7:11	4:48
31	9.6	7:11	4:48

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.8 kWh/m² — the year's lowest.

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 — December's 2.8 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	2.9	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.8	2.9	2.9	2.9	2.9	2.9	2.9	2.9	2.9	2.9
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	2.9	Moderate
2	2.8	Moderate
3	2.8	Moderate
4	2.8	Moderate
5	2.8	Moderate
6	2.8	Moderate
7	2.8	Moderate
8	2.8	Moderate
9	2.8	Moderate
10	2.8	Moderate
11	2.8	Moderate
12	2.8	Moderate
13	2.8	Moderate
14	2.8	Moderate
15	2.8	Moderate
16	2.8	Moderate
17	2.8	Moderate
18	2.8	Moderate
19	2.8	Moderate
20	2.8	Moderate
21	2.8	Moderate
22	2.8	Moderate
23	2.9	Moderate
24	2.9	Moderate
25	2.9	Moderate
26	2.9	Moderate
27	2.9	Moderate
28	2.9	Moderate
29	2.9	Moderate
30	2.9	Moderate
31	2.9	Moderate

Planning a trip in December

Is December a good time to visit Semnan?

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

2.3

Sightseeing

11th-best month of the year

0.0

Beach & pool

11th-best month of the year

December is a weaker month for outdoor sightseeing in Semnan.

What to pack for Semnan in December

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

In December, Semnan sees daytime highs around 9°C and nights near 1°C. Pack a warm layer. About 3 days see rain.

a warm layer

UV index in Semnan in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3 — 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	3	5	5	8	10	10	11	10	8	6	4	3
Level	Moderate	High	Moderate	Very high	Very high	Very high	Extreme	Extreme	Very high	High	Moderate	Moderate

	UV index (midday)	Level
Jan	3	Moderate
Feb	5	High
Mar	5	Moderate
Apr	8	Very high
May	10	Very high
Jun	10	Very high
Jul	11	Extreme
Aug	10	Extreme
Sep	8	Very high
Oct	6	High
Nov	4	Moderate
Dec	3	Moderate

Air quality in Semnan in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December 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).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	43	41	38	40	34	23	23	22	28	32	39	46
Level	Poor	Poor	Poor	Poor	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Poor	Poor

	PM2.5 (µg/m³)	Level
Jan	43	Poor
Feb	41	Poor
Mar	38	Poor
Apr	40	Poor
May	34	Moderate
Jun	23	Moderate
Jul	23	Moderate
Aug	22	Moderate
Sep	28	Moderate
Oct	32	Moderate
Nov	39	Poor
Dec	46	Poor

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.

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

artificial surfaces 59%

16 km

1,254 m

bare terrain 84%

80 km

3,375 m

bare terrain 67%

treesgrasslandcroplandartificial surfacesbare terrain

← November Semnan year-round climate January →Best places to visit in December

December 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

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).

	Avg high (°C)	Avg low (°C)
1	11	3
2	10	3
3	10	3
4	10	2
5	10	2
6	10	2
7	10	2
8	10	2
9	10	2
10	9	2
11	9	2
12	9	2
13	9	1
14	9	1
15	9	1
16	9	1
17	9	1
18	9	1
19	9	1
20	9	1
21	9	1
22	9	1
23	9	1
24	9	1
25	9	1
26	9	0
27	9	0
28	9	0
29	9	0
30	8	0
31	8	0

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	67	33
4	67	33
5	67	33
6	67	33
7	67	33
8	67	33
9	68	32
10	68	32
11	69	31
12	69	31
13	70	30
14	71	29
15	71	29
16	72	28
17	72	28
18	72	28
19	73	27
20	74	26
21	74	26
22	75	25
23	75	25
24	75	25
25	76	24
26	76	24
27	76	24
28	76	24
29	76	24
30	74	26
31	74	26

	Rain chance (%)	Snow chance (%)
1	11	2
2	11	2
3	11	2
4	11	2
5	11	2
6	11	2
7	11	2
8	11	3
9	11	3
10	11	3
11	11	3
12	10	3
13	10	3
14	10	3
15	10	3
16	10	3
17	10	3
18	10	3
19	10	3
20	10	3
21	9	3
22	9	3
23	9	3
24	9	3
25	9	3
26	9	3
27	9	3
28	9	3
29	9	3
30	9	3
31	9	3

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	11	3
2	10	3
3	10	3
4	10	2
5	10	2
6	10	2
7	10	2
8	10	2
9	10	2
10	9	2
11	9	2
12	9	2
13	9	1
14	9	1
15	9	1
16	9	1
17	9	1
18	9	1
19	9	1
20	9	1
21	9	1
22	9	1
23	9	1
24	9	1
25	9	1
26	9	0
27	9	0
28	9	0
29	9	0
30	8	0
31	8	0

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	67	33
4	67	33
5	67	33
6	67	33
7	67	33
8	67	33
9	68	32
10	68	32
11	69	31
12	69	31
13	70	30
14	71	29
15	71	29
16	72	28
17	72	28
18	72	28
19	73	27
20	74	26
21	74	26
22	75	25
23	75	25
24	75	25
25	76	24
26	76	24
27	76	24
28	76	24
29	76	24
30	74	26
31	74	26

	Rain chance (%)	Snow chance (%)
1	11	2
2	11	2
3	11	2
4	11	2
5	11	2
6	11	2
7	11	2
8	11	3
9	11	3
10	11	3
11	11	3
12	10	3
13	10	3
14	10	3
15	10	3
16	10	3
17	10	3
18	10	3
19	10	3
20	10	3
21	9	3
22	9	3
23	9	3
24	9	3
25	9	3
26	9	3
27	9	3
28	9	3
29	9	3
30	9	3
31	9	3

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	11	3
2	10	3
3	10	3
4	10	2
5	10	2
6	10	2
7	10	2
8	10	2
9	10	2
10	9	2
11	9	2
12	9	2
13	9	1
14	9	1
15	9	1
16	9	1
17	9	1
18	9	1
19	9	1
20	9	1
21	9	1
22	9	1
23	9	1
24	9	1
25	9	1
26	9	0
27	9	0
28	9	0
29	9	0
30	8	0
31	8	0

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	67	33
4	67	33
5	67	33
6	67	33
7	67	33
8	67	33
9	68	32
10	68	32
11	69	31
12	69	31
13	70	30
14	71	29
15	71	29
16	72	28
17	72	28
18	72	28
19	73	27
20	74	26
21	74	26
22	75	25
23	75	25
24	75	25
25	76	24
26	76	24
27	76	24
28	76	24
29	76	24
30	74	26
31	74	26

	Rain chance (%)	Snow chance (%)
1	11	2
2	11	2
3	11	2
4	11	2
5	11	2
6	11	2
7	11	2
8	11	3
9	11	3
10	11	3
11	11	3
12	10	3
13	10	3
14	10	3
15	10	3
16	10	3
17	10	3
18	10	3
19	10	3
20	10	3
21	9	3
22	9	3
23	9	3
24	9	3
25	9	3
26	9	3
27	9	3
28	9	3
29	9	3
30	9	3
31	9	3

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100