Mikkeli weather in September

In September, Mikkeli sees average daytime highs of 14°C and overnight lows near 8°C, with 54 mm of rain across 10.7 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 16°C in the first days to 11°C by the end. The sky is clear or mostly clear about 12% of the time in September, and the air most often feels dry.

Daylight stretches from about 14 h 06 min at the start of September to 11 h 12 min by month's end. Set against the rest of the year, September is Mikkeli's 7th-clearest and 7th-windiest month. For the whole year in context, see Mikkeli's year-round climate.

Daytime high
14°
4th warmest
Overnight low
9th coldest
Rainfall
54 mm
10.7 wet days
Daylight
12 h 36 min
5:48 AM – 6:22 PM
Cloud cover
74%
7th clearest
Wind
12 km/h
7th windiest
Solar energy
2.18 kWh/m²
Travel score
3.6
out of 10
Air quality
Excellent
PM10 12.5 µg/m³ · 2015

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 16°C in the first days to 11°C by the end.

A typical September day in Mikkeli reaches about 14°C in the afternoon and slips back to 8°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 9°C and 18°C. Set against its neighbours, September runs about 6°C cooler than August and about 7°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11710
21610
31610
41610
5169
6169
7159
8159
9159
10159
11158
12148
13148
14148
15148
16138
17137
18137
19137
20137
21127
22127
23126
24126
25126
26116
27116
28116
29116
30116

How September really feels in Mikkeli

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.

Mikkeli 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 (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-5° / -9°3910.411.15.90.0
Feb-4° / -10°328.59.48.40.0
Mar / -6°329.18.711.30.0
Apr / -1°348.73.714.30.7
May13° / 499.80.317.23.8
Jun18° / 11°7612.8018.95.3
Jul21° / 13°8212.8018.25.9
Aug19° / 12°7612.7015.65.6
Sep14° / 5410.7012.63.6
Oct / 5611.11.99.60.8
Nov / -2°5111.16.46.80.0
Dec-2° / -6°4611.610.850.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 12% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 73%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12674
22674
32872
42872
52872
62872
73070
83070
93070
103070
113070
123070
133070
143070
153070
162971
172971
182971
192971
202872
212872
222674
232674
242575
252575
262575
272476
282377
292377
302377

Chance of precipitation in September

Any precipitation

Mikkeli gets around 54 mm of rain over 10.7 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 36% and peaks near 38% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
138
238
338
438
538
638
738
838
938
1038
1138
1238
1337
1437
1537
1636
1736
1835
1935
2035
2134
2234
2333
2433
2533
2633
2733
2833
2934
3034

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 95% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
18218
28317
38515
48614
58713
68911
79010
8919
9928
10937
11946
12955
13955
14964
15973
16973
17982
18982
19982
20991
21991
22991
23991
24991
251000
261000
271000
281000
291000
301000

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
1712light breeze
1812light breeze
1912light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 14 h 06 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 174 minutes over September. Sunrise moves from 5:09 AM to 6:25 AM, and sunset from 7:13 PM to 5:36 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:097:13
214.05:117:09
313.95:147:06
413.85:177:03
513.75:196:59
613.65:226:56
713.55:246:53
813.45:276:49
913.35:306:46
1013.25:326:43
1113.15:356:39
1213.05:386:36
1312.95:406:33
1412.85:436:29
1512.75:456:26
1612.65:486:22
1712.55:516:19
1812.45:536:16
1912.35:566:12
2012.25:596:09
2112.16:016:06
2212.06:046:02
2311.96:065:59
2411.86:095:56
2511.76:125:52
2611.66:145:49
2711.56:175:46
2811.46:205:42
2911.36:225:39
3011.26:255:36

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.18 kWh/m².

For context, solar energy here swings from a low near 0.1 kWh/m² to a high of 5.33 kWh/m² in June across the year — September's 2.18 kWh/m² falls in the middle.

0123151015202530
Solar energy (kWh/m²)Level
12.9Moderate
22.9Moderate
32.8Moderate
42.7Moderate
52.7Moderate
62.6Moderate
72.6Moderate
82.5Moderate
92.5Moderate
102.4Moderate
112.4Moderate
122.3Moderate
132.3Moderate
142.3Moderate
152.2Moderate
162.2Moderate
172.1Moderate
182.1Moderate
192.0Moderate
202.0Dim
211.9Dim
221.9Dim
231.8Dim
241.8Dim
251.7Dim
261.7Dim
271.6Dim
281.6Dim
291.5Dim
301.5Dim
Planning a trip in September

Is September a good time to visit Mikkeli?

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

3.6
Sightseeing
5th-best month of the year
0.2
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in Mikkeli.

What to pack for Mikkeli in September

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

In September, Mikkeli sees daytime highs around 14°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 11 days see rain.

a warm layerrain gear

UV index in Mikkeli in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mikkeli peaks around June 21 at about 5 (moderate) — 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJun 21UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar1Low
Apr3Moderate
May4Moderate
Jun5Moderate
Jul5Moderate
Aug4Moderate
Sep2Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Mikkeli?

Mikkeli sits at 61.7°N, 27.3°E, 85 m above sea level, in Finland. The nearest listed city is Pieksämäki, 68 km away.

PieksämäkiVarkausHeinolaLappeenrantaSavonlinnaKouvolaImatraJyväskylä

Topography around Mikkeli

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

Within 3 km, the terrain around Mikkeli has only modest variations in elevation — a maximum elevation change of 57 m around an average of 94 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 110 m; within 80 km, only modest variations in elevation — a maximum elevation change of 184 m.

The land around Mikkeli is covered by trees (56%) and artificial surfaces (25%) within 3 km, trees (77%) within 16 km, and trees (74%) and water (22%) within 80 km.

3 km
57 m
16 km
110 m
80 km
184 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Pieksämäki 68 km · Varkaus 76 km · Heinola 85 km · Lappeenranta 85 km · Savonlinna 87 km · Kouvola 96 km · Imatra 97 km · Jyväskylä 102 km

Finland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 85% of US
price level, 2025
GDP per capita
$56,149
2025
Happiness
7.8 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1
per 100k, 2023
Road deaths
3.9
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 603
Religion
Lutheran 67%none 31%other 2%Greek Orthodox 1%

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 Mikkeli (61.6886°, 27.2723°, elevation 85 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).