Suwałki weather in September

In September, Suwałki sees average daytime highs of 17°C and overnight lows near 9°C, with 55 mm of rain across 9.1 wet days and about 12.5 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 15°C by the end. The sky is clear or mostly clear about 21% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 30 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Suwałki's 6th-clearest and 7th-windiest month. For the whole year in context, see Suwałki's year-round climate.

Daytime high
17°
5th warmest
Overnight low
9th coldest
Rainfall
55 mm
9.1 wet days
Daylight
12 h 24 min
5:10 AM – 5:35 PM
Cloud cover
66%
6th clearest
Wind
13 km/h
7th windiest
Solar energy
2.82 kWh/m²
Travel score
5.3
out of 10

Suwałki is town in Poland.

Air quality
Moderate
PM2.5 12 µg/m³ · 2019
Density
1,049/km²
people per km²
Founded
1690

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 19°C in the first days to 15°C by the end.

A typical September day in Suwałki reaches about 17°C in the afternoon and slips back to 9°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 12°C and 22°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12011
22011
31911
41910
51910
61910
71910
81810
91810
101810
11189
12189
13189
14179
15179
16179
17178
18178
19168
20168
21168
22168
23168
24167
25157
26157
27157
28157
29157
30147

How September really feels in Suwałki

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.

Suwałki weather by month

How September compares with the rest of the year at a glance. September is the 5th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -5°4110.97.57.70.0
Feb / -5°369.46.99.40.0
Mar / -2°3910.24.511.50.3
Apr12° / 429.21.213.73.1
May18° / 59120.115.75.4
Jun21° / 11°7211.9016.86.0
Jul23° / 13°8012.2016.46.4
Aug22° / 13°7211.7014.66.4
Sep17° / 559.1012.55.3
Oct11° / 5010.30.610.22.5
Nov / 399.73.18.30.2
Dec / -3°4310.16.27.20.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% 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 62%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14060
24060
33961
43961
53862
63862
73763
83763
93664
103664
113664
123664
133664
143763
153763
163763
173763
183862
193862
203862
213862
223862
233763
243763
253763
263763
273763
283664
293664
303664

Chance of precipitation in September

Any precipitation

Suwałki gets around 55 mm of rain over 9.1 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 31% and peaks near 37% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
137
236
336
435
535
635
734
834
934
1034
1133
1233
1333
1432
1531
1631
1730
1829
1929
2028
2128
2227
2327
2427
2527
2627
2727
2827
2928
3028

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 87% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
174233
275232
376222
477212
578202
679192
780182
880182
981172
1082162
1183152
1284142
1385132
1486122
1587112
1688111
1789101
189091
199181
209271
219271
229361
239550
249550
259640
269640
279640
289640
299730
309730

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 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
112light breeze
212light breeze
312light breeze
412light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light 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 30 min at the start of September to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 126 minutes over September. Sunrise moves from 4:42 AM to 5:36 AM, and sunset from 6:14 PM to 4:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.54:426:14
213.54:446:11
313.44:466:09
413.34:486:06
513.24:496:04
613.24:516:01
713.14:535:59
813.04:555:56
912.94:575:54
1012.94:595:51
1112.85:015:48
1212.75:025:46
1312.65:045:43
1412.65:065:41
1512.55:085:38
1612.45:105:35
1712.45:125:33
1812.35:135:30
1912.25:155:28
2012.15:175:25
2112.15:195:22
2212.05:215:20
2311.95:235:17
2411.85:255:15
2511.85:275:12
2611.75:285:09
2711.65:305:07
2811.55:325:04
2911.55:345:02
3011.45:364:59

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.82 kWh/m².

For context, solar energy here swings from a low near 0.43 kWh/m² to a high of 5.42 kWh/m² in June across the year — September's 2.82 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.4Moderate
33.4Moderate
43.3Moderate
53.3Moderate
63.3Moderate
73.2Moderate
83.2Moderate
93.1Moderate
103.1Moderate
113.0Moderate
123.0Moderate
132.9Moderate
142.9Moderate
152.9Moderate
162.8Moderate
172.8Moderate
182.7Moderate
192.7Moderate
202.6Moderate
212.6Moderate
222.6Moderate
232.5Moderate
242.5Moderate
252.4Moderate
262.4Moderate
272.3Moderate
282.3Moderate
292.3Moderate
302.2Moderate
Planning a trip in September

Is September a good time to visit Suwałki?

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

5.3
Sightseeing
5th-best month of the year
1.4
Beach & pool
5th-best month of the year

September is a reasonable time to visit Suwałki for sightseeing.

What to pack for Suwałki in September

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

In September, Suwałki sees daytime highs around 17°C and nights near 9°C. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Suwałki in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Suwałki peaks around June 23 at about 6 (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 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 23UV 6Dec 19UV 0
UV index (midday)Level
Jan1Low
Feb1Low
Mar2Moderate
Apr4Moderate
May5High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Low
Nov1Low
Dec0Low

Air quality in Suwałki in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Suwałki is worst in July — around 15 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 7 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Suwałki's WHO annual average of 12 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1315 µg/m³Dec 167 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb11Good
Mar15Moderate
Apr15Moderate
May14Moderate
Jun15Moderate
Jul15Moderate
Aug14Moderate
Sep12Moderate
Oct9Good
Nov8Good
Dec7Good
Location & terrain

Where is Suwałki?

Suwałki sits at 54.1°N, 22.9°E, 177 m above sea level, in Poland. The nearest listed city is Olecko, 29 km away.

EłkMarijampolėGrajewoGusevGrodnoGiżycko

Topography around Suwałki

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

Within 3 km, the terrain around Suwałki has only modest variations in elevation — a maximum elevation change of 64 m around an average of 176 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 160 m; within 80 km, significant variations in elevation — a maximum elevation change of 292 m.

The land around Suwałki is covered by artificial surfaces (32%), grassland (30%) and cropland (20%) within 3 km, grassland (34%), trees (30%) and cropland (27%) within 16 km, and trees (36%), cropland (31%) and grassland (29%) within 80 km.

3 km
64 m
16 km
160 m
80 km
292 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Olecko 29 km · Augustów 30 km · Ełk 49 km · Marijampolė 57 km · Grajewo 60 km · Gusev 71 km · Grodno 76 km · Giżycko 77 km

Poland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 52% of US
price level, 2025
GDP per capita
$28,420
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
0.8
per 100k, 2023
Road deaths
9.4
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 600
Religion
Roman Catholic 71%refused to answer 21%no religion 7%

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 Suwałki (54.1118°, 22.9309°, elevation 177 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).