Lohja weather in September

In September, Lohja sees average daytime highs of 15°C and overnight lows near 8°C, with 55 mm of rain across 10 wet days and about 12.6 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 17°C in the first days to 12°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 Lohja's 7th-clearest and 7th-windiest month. For the whole year in context, see Lohja's year-round climate.

Daytime high
15°
4th warmest
Overnight low
9th coldest
Rainfall
55 mm
10 wet days
Daylight
12 h 30 min
6:02 AM – 6:34 PM
Cloud cover
68%
7th clearest
Wind
14 km/h
7th windiest
Solar energy
2.46 kWh/m²
Travel score
4.3
out of 10
Air quality
Good
PM2.5 5.2 µg/m³ · 2019

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 17°C in the first days to 12°C by the end.

A typical September day in Lohja reaches about 15°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 11°C and 18°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)
11711
21710
31710
41710
51710
61710
71610
81610
9169
10169
11169
12159
13159
14159
15158
16158
17148
18148
19148
20148
21147
22147
23137
24137
25137
26137
27137
28127
29126
30126

How September really feels in Lohja

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.

Lohja weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -6°52119.76.30.0
Feb-2° / -7°428.98.78.60.0
Mar / -5°388.26.711.30.0
Apr / -0°358.52.414.21.2
May14° / 429.10.116.84.1
Jun18° / 10°6511018.45.6
Jul21° / 13°7010.9017.86.4
Aug20° / 12°7311.8015.45.9
Sep15° / 5510012.64.3
Oct / 6110.60.69.71.5
Nov / 5911.64.87.10.0
Dec / -3°5812.385.60.0

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 16% of September, with mostly cloudy or overcast conditions the remaining 65%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13268
23268
33367
43466
53466
63565
73664
83664
93763
103763
113763
123763
133862
143862
153763
163763
173664
183664
193565
203565
213466
223466
233466
243367
253367
263367
273367
283268
293169
303169

Chance of precipitation in September

Any precipitation

Lohja gets around 55 mm of rain over 10 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 34% and peaks near 38% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
138
238
338
437
537
637
737
837
937
1037
1137
1236
1335
1435
1534
1633
1733
1832
1931
2031
2130
2230
2330
2430
2530
2630
2730
2830
2931
3031

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 89% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
172253
274242
376222
477212
579201
680191
781181
882171
983161
1085150
1186140
1287130
1389110
1490100
159190
169280
179370
189460
199550
209550
219640
229640
239730
249730
259730
269820
279820
289820
299820
309820

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light 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 5:25 AM to 6:36 AM, and sunset from 7:22 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:257:22
213.95:287:19
313.85:307:16
413.75:327:12
513.65:357:09
613.55:377:06
713.45:407:03
813.35:427:00
913.25:456:57
1013.15:476:53
1113.05:506:50
1212.95:526:47
1312.85:546:44
1412.75:576:41
1512.65:596:37
1612.56:026:34
1712.46:046:31
1812.46:076:28
1912.36:096:25
2012.26:126:22
2112.16:146:18
2212.06:176:15
2311.96:196:12
2411.86:216:09
2511.76:246:06
2611.66:266:02
2711.56:295:59
2811.46:315:56
2911.36:345:53
3011.26:365:50

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.46 kWh/m².

For context, solar energy here swings from a low near 0.16 kWh/m² to a high of 5.68 kWh/m² in June across the year — September's 2.46 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.2Moderate
23.1Moderate
33.1Moderate
43.0Moderate
53.0Moderate
62.9Moderate
72.9Moderate
82.8Moderate
92.8Moderate
102.7Moderate
112.7Moderate
122.6Moderate
132.6Moderate
142.5Moderate
152.5Moderate
162.5Moderate
172.4Moderate
182.4Moderate
192.3Moderate
202.3Moderate
212.2Moderate
222.2Moderate
232.1Moderate
242.1Moderate
252.0Moderate
262.0Dim
271.9Dim
281.9Dim
291.8Dim
301.8Dim
Planning a trip in September

Is September a good time to visit Lohja?

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

4.3
Sightseeing
4th-best month of the year
0.4
Beach & pool
4th-best month of the year

September is a reasonable time to visit Lohja for sightseeing.

What to pack for Lohja in September

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

In September, Lohja sees daytime highs around 15°C and nights near 8°C. Worth packing: a warm layer and rain gear. About 10 days see rain.

a warm layerrain gear

Sea temperature near Lohja 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 34 km away) is warmest in August at about 17°C and coldest in March near 1°C.

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

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan2Bracing
Feb1Bracing
Mar1Bracing
Apr2Bracing
May6Bracing
Jun11Bracing
Jul16Cool
Aug17Cool
Sep14Bracing
Oct10Bracing
Nov7Bracing
Dec4Bracing

UV index in Lohja 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 Lohja peaks around June 17 at about 5 (high) — 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 17UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Lohja?

Lohja sits at 60.2°N, 24.1°E, 82 m above sea level, in Finland. The nearest listed city is Vihti, 23 km away.

Topography around Lohja

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

Within 3 km, the terrain around Lohja has only modest variations in elevation — a maximum elevation change of 85 m around an average of 52 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 127 m; within 80 km, only modest variations in elevation — a maximum elevation change of 194 m.

The land around Lohja is covered by trees (53%) and water (21%) within 3 km, trees (63%) within 16 km, and trees (49%) and water (35%) within 80 km.

3 km
85 m
16 km
127 m
80 km
194 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Vihti 23 km · Kirkkonummi 25 km · Espoo 33 km · Espoonlahti 34 km · Olari 38 km · Matinkylä 39 km · Klaukkala 41 km · Leppävaara 41 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 Lohja (60.2486°, 24.0653°, elevation 82 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).