Märsta weather in September

In September, Märsta sees average daytime highs of 16°C and overnight lows near 8°C, with 50 mm of rain across 8.5 wet days and about 12.6 hours of daylight. It is the 4th-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 14°C by the end. The sky is clear or mostly clear about 19% 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 Märsta's 5th-clearest and 8th-windiest month. For the whole year in context, see Märsta's year-round climate.

Daytime high
16°
4th warmest
Overnight low
9th coldest
Rainfall
50 mm
8.5 wet days
Daylight
12 h 30 min
5:27 AM – 5:59 PM
Cloud cover
66%
5th clearest
Wind
12 km/h
8th windiest
Solar energy
2.56 kWh/m²
Travel score
5.0
out of 10

Märsta is urban area in Sigtuna Municipality, Sweden.

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 18°C in the first days to 14°C by the end.

A typical September day in Märsta reaches about 16°C in the afternoon and slips back to 8°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 20°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11910
21910
3189
4189
5189
6189
7189
8189
9179
10178
11178
12178
13178
14168
15168
16168
17167
18167
19167
20157
21157
22157
23157
24156
25146
26146
27146
28146
29146
30136

How September really feels in Märsta

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
0
heat index over the day's high
Days feeling ≤ C
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.

Märsta weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°3485.66.50.0
Feb / -5°287.66.18.70.0
Mar / -3°297.44.611.30.2
Apr10° / 338.11.614.12.5
May16° / 459.40.216.75.1
Jun20° / 10°6710.8018.26.0
Jul22° / 12°7011.5017.66.4
Aug21° / 11°6912.1015.36.1
Sep16° / 508.5012.65.0
Oct10° / 489.40.29.82.1
Nov / 449.72.97.30.1
Dec / -3°42105.65.80.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 62%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43862
53862
63862
73961
83961
94060
104060
113961
123862
133862
143961
153961
163961
173961
183862
193862
203862
213763
223763
233763
243763
253763
263664
273664
283664
293664
303565

Chance of precipitation in September

Any precipitation

Märsta gets around 50 mm of rain over 8.5 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 30% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
135
234
333
432
532
631
730
830
930
1030
1129
1229
1329
1429
1529
1629
1728
1828
1928
2028
2128
2228
2328
2428
2528
2628
2729
2829
2929
3030

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 92% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
179183
280173
382162
483152
584142
685141
786131
887121
988111
1090100
119190
129190
139280
149370
159460
169460
179550
189550
199640
209640
219640
229730
239730
249730
259730
269820
279820
289820
299820
309820

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012light breeze

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 4:51 AM to 6:01 AM, and sunset from 6:45 PM to 5:15 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.94:516:45
213.84:546:42
313.74:566:39
413.64:596:36
513.55:016:33
613.45:036:30
713.45:066:27
813.35:086:24
913.25:106:21
1013.15:136:17
1113.05:156:14
1212.95:186:11
1312.85:206:08
1412.75:226:05
1512.65:256:02
1612.55:275:59
1712.45:295:56
1812.35:325:52
1912.35:345:49
2012.25:375:46
2112.15:395:43
2212.05:415:40
2311.95:445:37
2411.85:465:34
2511.75:495:31
2611.65:515:28
2711.55:535:24
2811.45:565:21
2911.35:585:18
3011.26:015:15

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.56 kWh/m².

For context, solar energy here swings from a low near 0.2 kWh/m² to a high of 5.57 kWh/m² in June across the year — September's 2.56 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.3Moderate
23.2Moderate
33.1Moderate
43.1Moderate
53.0Moderate
63.0Moderate
73.0Moderate
82.9Moderate
92.9Moderate
102.8Moderate
112.8Moderate
122.7Moderate
132.7Moderate
142.6Moderate
152.6Moderate
162.5Moderate
172.5Moderate
182.5Moderate
192.4Moderate
202.4Moderate
212.3Moderate
222.3Moderate
232.2Moderate
242.2Moderate
252.1Moderate
262.1Moderate
272.0Moderate
282.0Dim
291.9Dim
301.9Dim
Planning a trip in September

Is September a good time to visit Märsta?

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

5.0
Sightseeing
5th-best month of the year
0.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Märsta for sightseeing.

What to pack for Märsta in September

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

In September, Märsta sees daytime highs around 16°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 9 days see rain.

a warm layerrain gear

Sea temperature near Märsta in September

The nearest coast averages about 14°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 57 km away) is warmest in August at about 17°C and coldest in February near 1°C.

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

0°5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan3Bracing
Feb1Bracing
Mar2Bracing
Apr3Bracing
May6Bracing
Jun11Bracing
Jul16Cool
Aug17Cool
Sep14Bracing
Oct10Bracing
Nov7Bracing
Dec4Bracing

UV index in Märsta 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 Märsta peaks around June 17 at about 5 (high) — a little sun protection helps at midday. It bottoms out near December 19 at about 0 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 17UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Märsta?

Märsta sits at 59.6°N, 17.9°E, 19 m above sea level, in Sweden. The nearest listed city is Upplands Väsby, 12 km away.

Topography around Märsta

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

Within 3 km, the terrain around Märsta has only modest variations in elevation — a maximum elevation change of 66 m around an average of 26 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 74 m; within 80 km, only modest variations in elevation — a maximum elevation change of 146 m.

The land around Märsta is covered by trees (38%) and grassland (28%) within 3 km, trees (52%) within 16 km, and trees (54%) and water (24%) within 80 km.

3 km
66 m
16 km
74 m
80 km
146 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Upplands Väsby 12 km · Vallentuna 16 km · Jakobsberg 22 km · Sollentuna 22 km · Täby 23 km · Tensta 25 km · Danderyd 26 km · Rinkeby 26 km

Sweden travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 87% of US
price level, 2025
GDP per capita
$63,133
2025
Happiness
7.3 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2023
Road deaths
3.1
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 609
Religion
Church of Sweden 54%none or unspecified 37%other 9%

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 Märsta (59.6216°, 17.8548°, elevation 19 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).