Asker weather in September

In September, Asker sees average daytime highs of 16°C and overnight lows near 9°C, with 86 mm of rain across 10.3 wet days and about 12.6 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 13°C by the end. The sky is clear or mostly clear about 25% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 54 min at the start of September to 11 h 12 min by month's end. Set against the rest of the year, September is Asker's 6th-clearest and 1st-windiest month. For the whole year in context, see Asker's year-round climate.

Daytime high: 16°; 4th warmest
Overnight low: 9°; 9th coldest
Rainfall: 86 mm; 10.3 wet days
Daylight: 12 h 30 min; 5:57 AM – 6:29 PM
Cloud cover: 64%; 6th clearest
Wind: 9 km/h; 1st windiest
Solar energy: 2.49 kWh/m²
Travel score: 4.7; out of 10

Asker is Municipal centre of Asker Municipality, Norway.

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

← August Asker year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 18°C in the first days to 13°C by the end.

A typical September day in Asker reaches about 16°C in the afternoon and slips back to 9°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 19°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

	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
Avg high (°C)	18	18	18	17	17	17	17	17	17	17	16	16	16	16	16	16	15	15	15	15	15	15	14	14	14	14	14	13	13	13
Avg low (°C)	11	11	11	10	10	10	10	10	10	10	10	9	9	9	9	9	9	9	8	8	8	8	8	8	8	7	7	7	7	7

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

How September really feels in Asker

Once humidity and wind are folded in, September 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

heat index over the day's high

Days feeling ≤ 0°C

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.

Asker 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.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	-1° / -6°	73	11.1	9.7	6.4	0.0
Feb	0° / -6°	51	8.5	7.7	8.7	0.0
Mar	5° / -3°	53	8.1	6	11.3	0.2
Apr	10° / 1°	51	8.4	2.3	14.1	2.3
May	15° / 6°	71	10.4	0.6	16.7	4.6
Jun	19° / 10°	85	11.5	0	18.3	5.8
Jul	21° / 13°	92	11.8	0	17.6	6.2
Aug	20° / 13°	96	12.9	0	15.3	5.9
Sep	16° / 9°	86	10.3	0	12.6	4.7
Oct	10° / 4°	91	11.6	1.1	9.8	1.9
Nov	4° / 0°	90	11.9	4.9	7.2	0.1
Dec	0° / -4°	70	11.1	7.1	5.7	0.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% 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 59%.

	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
Clearer (%)	43	43	43	44	43	43	43	43	42	43	43	43	43	43	42	42	42	42	42	41	40	40	40	40	39	39	37	37	36	37
Cloudier (%)	57	57	57	56	57	57	57	57	58	57	57	57	57	57	58	58	58	58	58	59	60	60	60	60	61	61	63	63	64	63

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	44	56
5	43	57
6	43	57
7	43	57
8	43	57
9	42	58
10	43	57
11	43	57
12	43	57
13	43	57
14	43	57
15	42	58
16	42	58
17	42	58
18	42	58
19	42	58
20	41	59
21	40	60
22	40	60
23	40	60
24	40	60
25	39	61
26	39	61
27	37	63
28	37	63
29	36	64
30	37	63

Chance of precipitation in September

Any precipitation

Asker gets around 86 mm of rain over 10.3 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 35% and peaks near 37% on the wettest days.

	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
Rain chance (%)	37	37	37	37	36	36	36	36	36	36	36	36	36	36	35	35	35	34	34	34	34	33	34	34	34	34	35	35	36	36

	Rain chance (%)
1	37
2	37
3	37
4	37
5	36
6	36
7	36
8	36
9	36
10	36
11	36
12	36
13	36
14	36
15	35
16	35
17	35
18	34
19	34
20	34
21	34
22	33
23	34
24	34
25	34
26	34
27	35
28	35
29	36
30	36

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 94% 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
Dry (%)	84	85	86	88	89	90	90	91	92	92	93	93	94	94	95	95	95	96	96	96	97	97	97	97	97	97	97	98	98	98
Comfortable (%)	14	13	12	11	10	9	9	8	8	8	7	7	6	6	5	5	5	4	4	4	3	3	3	3	3	3	3	2	2	2
Humid (%)	2	2	2	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

	Dry (%)	Comfortable (%)	Humid (%)
1	84	14	2
2	85	13	2
3	86	12	2
4	88	11	1
5	89	10	1
6	90	9	1
7	90	9	1
8	91	8	1
9	92	8	0
10	92	8	0
11	93	7	0
12	93	7	0
13	94	6	0
14	94	6	0
15	95	5	0
16	95	5	0
17	95	5	0
18	96	4	0
19	96	4	0
20	96	4	0
21	97	3	0
22	97	3	0
23	97	3	0
24	97	3	0
25	97	3	0
26	97	3	0
27	97	3	0
28	98	2	0
29	98	2	0
30	98	2	0

Wind in September

Winds average 9 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 9 km/h on the calmest days to 9 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
Wind speed (km/h)	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9
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

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

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 54 min at the start of September to 11 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 162 minutes over September. Sunrise moves from 5:21 AM to 6:30 AM, and sunset from 7:15 PM to 5:45 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
Daylight (h)	13.9	13.8	13.7	13.6	13.5	13.5	13.4	13.3	13.2	13.1	13.0	12.9	12.8	12.7	12.6	12.5	12.4	12.3	12.3	12.2	12.1	12.0	11.9	11.8	11.7	11.6	11.5	11.4	11.3	11.2
Sunrise (AM)	5:21	5:23	5:25	5:28	5:30	5:33	5:35	5:37	5:40	5:42	5:45	5:47	5:49	5:52	5:54	5:57	5:59	6:01	6:04	6:06	6:09	6:11	6:13	6:16	6:18	6:21	6:23	6:26	6:28	6:30
Sunset (PM)	7:15	7:12	7:09	7:06	7:03	7:00	6:57	6:54	6:51	6:47	6:44	6:41	6:38	6:35	6:32	6:29	6:25	6:22	6:19	6:16	6:13	6:10	6:07	6:03	6:00	5:57	5:54	5:51	5:48	5:45

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.9	5:21	7:15
2	13.8	5:23	7:12
3	13.7	5:25	7:09
4	13.6	5:28	7:06
5	13.5	5:30	7:03
6	13.5	5:33	7:00
7	13.4	5:35	6:57
8	13.3	5:37	6:54
9	13.2	5:40	6:51
10	13.1	5:42	6:47
11	13.0	5:45	6:44
12	12.9	5:47	6:41
13	12.8	5:49	6:38
14	12.7	5:52	6:35
15	12.6	5:54	6:32
16	12.5	5:57	6:29
17	12.4	5:59	6:25
18	12.3	6:01	6:22
19	12.3	6:04	6:19
20	12.2	6:06	6:16
21	12.1	6:09	6:13
22	12.0	6:11	6:10
23	11.9	6:13	6:07
24	11.8	6:16	6:03
25	11.7	6:18	6:00
26	11.6	6:21	5:57
27	11.5	6:23	5:54
28	11.4	6:26	5:51
29	11.3	6:28	5:48
30	11.2	6:30	5:45

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.49 kWh/m².

For context, solar energy here swings from a low near 0.2 kWh/m² to a high of 5.59 kWh/m² in June across the year — September's 2.49 kWh/m² falls in the middle.

	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
Solar energy (kWh/m²)	3.2	3.2	3.1	3.1	3.0	3.0	2.9	2.9	2.8	2.8	2.7	2.6	2.6	2.5	2.5	2.5	2.4	2.4	2.3	2.3	2.2	2.2	2.1	2.1	2.0	2.0	1.9	1.9	1.8	1.8
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	Dim	Dim	Dim	Dim	Dim

	Solar energy (kWh/m²)	Level
1	3.2	Moderate
2	3.2	Moderate
3	3.1	Moderate
4	3.1	Moderate
5	3.0	Moderate
6	3.0	Moderate
7	2.9	Moderate
8	2.9	Moderate
9	2.8	Moderate
10	2.8	Moderate
11	2.7	Moderate
12	2.6	Moderate
13	2.6	Moderate
14	2.5	Moderate
15	2.5	Moderate
16	2.5	Moderate
17	2.4	Moderate
18	2.4	Moderate
19	2.3	Moderate
20	2.3	Moderate
21	2.2	Moderate
22	2.2	Moderate
23	2.1	Moderate
24	2.1	Moderate
25	2.0	Moderate
26	2.0	Dim
27	1.9	Dim
28	1.9	Dim
29	1.8	Dim
30	1.8	Dim

Planning a trip in September

Is September a good time to visit Asker?

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

4.7

Sightseeing

4th-best month of the year

0.6

Beach & pool

4th-best month of the year

September is a reasonable time to visit Asker for sightseeing.

What to pack for Asker in September

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

In September, Asker sees daytime highs around 16°C and nights near 9°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Asker in September

The nearest coast averages about 15°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 52 km away) is warmest in August at about 18°C and coldest in February near 3°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	4	3	3	6	11	15	18	18	15	12	9	6
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Cool	Cool	Cool	Cool	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	4	Bracing
Feb	3	Bracing
Mar	3	Bracing
Apr	6	Bracing
May	11	Bracing
Jun	15	Cool
Jul	18	Cool
Aug	18	Cool
Sep	15	Cool
Oct	12	Bracing
Nov	9	Bracing
Dec	6	Bracing

UV index in Asker in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 3. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Asker peaks around July 17 at about 5 (moderate) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 4 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	0	1	2	3	4	4	5	4	3	1	0	0
Level	Low	Low	Low	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Low	Low	Low

	UV index (midday)	Level
Jan	0	Low
Feb	1	Low
Mar	2	Low
Apr	3	Moderate
May	4	Moderate
Jun	4	Moderate
Jul	5	Moderate
Aug	4	Moderate
Sep	3	Moderate
Oct	1	Low
Nov	0	Low
Dec	0	Low

Location & terrain

Where is Asker?

Asker sits at 59.8°N, 10.4°E, 119 m above sea level, in Norway. The nearest listed city is Drammen, 16 km away.

Topography around Asker

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

Within 3 km, the terrain around Asker has significant variations in elevation — a maximum elevation change of 345 m around an average of 129 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 599 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,482 m.

The land around Asker is covered by trees (62%) within 3 km, trees (60%) and water (22%) within 16 km, and trees (73%) within 80 km.

3 km

345 m

trees 62%

16 km

599 m

trees 60%

80 km

1,482 m

trees 73%

treesgrasslandcroplandartificial surfaceswater

← August Asker year-round climate October →Best places to visit in September

September weather nearby: Drammen 16 km · Oslo 19 km · Lillestrøm 37 km · Moss 46 km · Horten 46 km · Kongsberg 48 km · Tønsberg 63 km · Sarpsborg 72 km

Norway travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type C / F; 230 V · 50 Hz
Prices: ≈ 91% of US; price level, 2025
GDP per capita: $94,594; 2025
Happiness: 7.2 / 10; World Happiness, 2025
Safe drinking water: 99%; of population, 2024
Homicide rate: 0.7; per 100k, 2023
Road deaths: 2.1; per 100k/yr, 2019
Income group: High; World Bank
English: Very high; EF EPI 613
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 Asker (59.8333°, 10.4372°, elevation 119 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. 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	18	11
2	18	11
3	18	11
4	17	10
5	17	10
6	17	10
7	17	10
8	17	10
9	17	10
10	17	10
11	16	10
12	16	9
13	16	9
14	16	9
15	16	9
16	16	9
17	15	9
18	15	9
19	15	8
20	15	8
21	15	8
22	15	8
23	14	8
24	14	8
25	14	8
26	14	7
27	14	7
28	13	7
29	13	7
30	13	7

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	44	56
5	43	57
6	43	57
7	43	57
8	43	57
9	42	58
10	43	57
11	43	57
12	43	57
13	43	57
14	43	57
15	42	58
16	42	58
17	42	58
18	42	58
19	42	58
20	41	59
21	40	60
22	40	60
23	40	60
24	40	60
25	39	61
26	39	61
27	37	63
28	37	63
29	36	64
30	37	63

	Rain chance (%)
1	37
2	37
3	37
4	37
5	36
6	36
7	36
8	36
9	36
10	36
11	36
12	36
13	36
14	36
15	35
16	35
17	35
18	34
19	34
20	34
21	34
22	33
23	34
24	34
25	34
26	34
27	35
28	35
29	36
30	36

	Dry (%)	Comfortable (%)	Humid (%)
1	84	14	2
2	85	13	2
3	86	12	2
4	88	11	1
5	89	10	1
6	90	9	1
7	90	9	1
8	91	8	1
9	92	8	0
10	92	8	0
11	93	7	0
12	93	7	0
13	94	6	0
14	94	6	0
15	95	5	0
16	95	5	0
17	95	5	0
18	96	4	0
19	96	4	0
20	96	4	0
21	97	3	0
22	97	3	0
23	97	3	0
24	97	3	0
25	97	3	0
26	97	3	0
27	97	3	0
28	98	2	0
29	98	2	0
30	98	2	0

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

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	44	56
5	43	57
6	43	57
7	43	57
8	43	57
9	42	58
10	43	57
11	43	57
12	43	57
13	43	57
14	43	57
15	42	58
16	42	58
17	42	58
18	42	58
19	42	58
20	41	59
21	40	60
22	40	60
23	40	60
24	40	60
25	39	61
26	39	61
27	37	63
28	37	63
29	36	64
30	37	63

	Rain chance (%)
1	37
2	37
3	37
4	37
5	36
6	36
7	36
8	36
9	36
10	36
11	36
12	36
13	36
14	36
15	35
16	35
17	35
18	34
19	34
20	34
21	34
22	33
23	34
24	34
25	34
26	34
27	35
28	35
29	36
30	36

	Dry (%)	Comfortable (%)	Humid (%)
1	84	14	2
2	85	13	2
3	86	12	2
4	88	11	1
5	89	10	1
6	90	9	1
7	90	9	1
8	91	8	1
9	92	8	0
10	92	8	0
11	93	7	0
12	93	7	0
13	94	6	0
14	94	6	0
15	95	5	0
16	95	5	0
17	95	5	0
18	96	4	0
19	96	4	0
20	96	4	0
21	97	3	0
22	97	3	0
23	97	3	0
24	97	3	0
25	97	3	0
26	97	3	0
27	97	3	0
28	98	2	0
29	98	2	0
30	98	2	0

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

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	44	56
5	43	57
6	43	57
7	43	57
8	43	57
9	42	58
10	43	57
11	43	57
12	43	57
13	43	57
14	43	57
15	42	58
16	42	58
17	42	58
18	42	58
19	42	58
20	41	59
21	40	60
22	40	60
23	40	60
24	40	60
25	39	61
26	39	61
27	37	63
28	37	63
29	36	64
30	37	63

	Rain chance (%)
1	37
2	37
3	37
4	37
5	36
6	36
7	36
8	36
9	36
10	36
11	36
12	36
13	36
14	36
15	35
16	35
17	35
18	34
19	34
20	34
21	34
22	33
23	34
24	34
25	34
26	34
27	35
28	35
29	36
30	36

	Dry (%)	Comfortable (%)	Humid (%)
1	84	14	2
2	85	13	2
3	86	12	2
4	88	11	1
5	89	10	1
6	90	9	1
7	90	9	1
8	91	8	1
9	92	8	0
10	92	8	0
11	93	7	0
12	93	7	0
13	94	6	0
14	94	6	0
15	95	5	0
16	95	5	0
17	95	5	0
18	96	4	0
19	96	4	0
20	96	4	0
21	97	3	0
22	97	3	0
23	97	3	0
24	97	3	0
25	97	3	0
26	97	3	0
27	97	3	0
28	98	2	0
29	98	2	0
30	98	2	0