Brno weather in September

In September, Brno sees average daytime highs of 19°C and overnight lows near 10°C, with 64 mm of rain across 9.5 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 21°C in the first days to 16°C by the end. The sky is clear or mostly clear about 27% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Brno's 4th-clearest and 9th-windiest month. For the whole year in context, see Brno's year-round climate.

Daytime high: 19°; 4th warmest
Overnight low: 10°; 9th coldest
Rainfall: 64 mm; 9.5 wet days
Daylight: 12 h 24 min; 5:37 AM – 5:59 PM
Cloud cover: 61%; 4th clearest
Wind: 11 km/h; 9th windiest
Solar energy: 3.3 kWh/m²
Travel score: 5.9; out of 10

Brno is city in the Czech Republic.

Air quality: Elevated; PM2.5 15.4 µg/m³ · 2019
Density: 1,649/km²; people per km²
Founded: 1243

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

← August Brno 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 21°C in the first days to 16°C by the end.

A typical September day in Brno reaches about 19°C in the afternoon and slips back to 10°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 24°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)	21	21	21	21	20	20	20	20	20	20	19	19	19	19	19	18	18	18	18	18	18	17	17	17	17	17	17	16	16	16
Avg low (°C)	12	12	12	12	12	12	11	11	11	11	11	11	11	10	10	10	10	10	10	9	9	9	9	9	9	9	9	8	8	8

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

How September really feels in Brno

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.

Brno 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° / -4°	34	8.8	5.6	8.5	0.0
Feb	3° / -3°	27	7.2	4.2	9.8	0.0
Mar	8° / 1°	40	8.8	2.5	11.6	1.3
Apr	14° / 5°	40	9.2	0.7	13.4	4.0
May	18° / 9°	65	12.4	0	15.1	5.6
Jun	22° / 13°	75	12.4	0	15.9	6.2
Jul	24° / 14°	84	13	0	15.6	6.6
Aug	24° / 14°	69	10.4	0	14.2	6.8
Sep	19° / 10°	64	9.5	0	12.4	5.9
Oct	12° / 6°	44	8.9	0.3	10.5	3.4
Nov	6° / 2°	41	9	2.3	8.9	0.7
Dec	2° / -2°	36	9	4.8	8.1	0.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% 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 56%.

	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 (%)	49	49	48	48	47	47	47	47	46	45	45	45	45	44	45	44	43	43	43	43	43	42	42	42	41	41	41	40	40	39
Cloudier (%)	51	51	52	52	53	53	53	53	54	55	55	55	55	56	55	56	57	57	57	57	57	58	58	58	59	59	59	60	60	61

	Clearer (%)	Cloudier (%)
1	49	51
2	49	51
3	48	52
4	48	52
5	47	53
6	47	53
7	47	53
8	47	53
9	46	54
10	45	55
11	45	55
12	45	55
13	45	55
14	44	56
15	45	55
16	44	56
17	43	57
18	43	57
19	43	57
20	43	57
21	43	57
22	42	58
23	42	58
24	42	58
25	41	59
26	41	59
27	41	59
28	40	60
29	40	60
30	39	61

Chance of precipitation in September

Any precipitation

Brno gets around 64 mm of rain over 9.5 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 32% and peaks near 34% 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 (%)	34	34	34	34	34	34	34	34	34	34	34	33	33	32	32	32	32	32	31	31	30	30	29	29	29	29	29	30	30	31

	Rain chance (%)
1	34
2	34
3	34
4	34
5	34
6	34
7	34
8	34
9	34
10	34
11	34
12	33
13	33
14	32
15	32
16	32
17	32
18	32
19	31
20	31
21	30
22	30
23	29
24	29
25	29
26	29
27	29
28	30
29	30
30	31

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 85% 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 (%)	72	73	74	76	77	77	79	79	80	81	82	82	83	84	85	87	87	88	89	90	91	92	93	93	94	94	95	95	95	95
Comfortable (%)	22	22	21	20	20	20	19	19	18	18	17	17	16	15	14	13	13	12	11	10	9	8	7	7	6	6	5	5	5	5
Humid (%)	6	5	5	4	3	3	2	2	2	1	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

	Dry (%)	Comfortable (%)	Humid (%)
1	72	22	6
2	73	22	5
3	74	21	5
4	76	20	4
5	77	20	3
6	77	20	3
7	79	19	2
8	79	19	2
9	80	18	2
10	81	18	1
11	82	17	1
12	82	17	1
13	83	16	1
14	84	15	1
15	85	14	1
16	87	13	0
17	87	13	0
18	88	12	0
19	89	11	0
20	90	10	0
21	91	9	0
22	92	8	0
23	93	7	0
24	93	7	0
25	94	6	0
26	94	6	0
27	95	5	0
28	95	5	0
29	95	5	0
30	95	5	0

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 11 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)	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11
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	11	calm
2	11	calm
3	11	calm
4	11	calm
5	11	calm
6	11	calm
7	11	calm
8	11	calm
9	11	calm
10	11	calm
11	11	calm
12	11	calm
13	11	calm
14	11	calm
15	11	calm
16	11	calm
17	11	calm
18	11	calm
19	11	calm
20	11	calm
21	11	calm
22	11	calm
23	11	calm
24	11	calm
25	11	calm
26	11	calm
27	11	calm
28	11	calm
29	11	calm
30	11	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 18 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 108 minutes over September. Sunrise moves from 5:15 AM to 5:58 AM, and sunset from 6:32 PM to 5:27 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)	13.3	13.2	13.2	13.1	13.0	13.0	12.9	12.9	12.8	12.7	12.7	12.6	12.5	12.5	12.4	12.4	12.3	12.2	12.2	12.1	12.0	12.0	11.9	11.9	11.8	11.7	11.7	11.6	11.5	11.5
Sunrise (AM)	5:15	5:16	5:18	5:19	5:21	5:22	5:24	5:25	5:27	5:28	5:30	5:31	5:33	5:34	5:36	5:37	5:39	5:40	5:42	5:43	5:45	5:46	5:48	5:49	5:51	5:52	5:54	5:55	5:57	5:58
Sunset (PM)	6:32	6:30	6:27	6:25	6:23	6:21	6:19	6:16	6:14	6:12	6:10	6:08	6:05	6:03	6:01	5:59	5:56	5:54	5:52	5:50	5:47	5:45	5:43	5:41	5:39	5:36	5:34	5:32	5:30	5:27

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.3	5:15	6:32
2	13.2	5:16	6:30
3	13.2	5:18	6:27
4	13.1	5:19	6:25
5	13.0	5:21	6:23
6	13.0	5:22	6:21
7	12.9	5:24	6:19
8	12.9	5:25	6:16
9	12.8	5:27	6:14
10	12.7	5:28	6:12
11	12.7	5:30	6:10
12	12.6	5:31	6:08
13	12.5	5:33	6:05
14	12.5	5:34	6:03
15	12.4	5:36	6:01
16	12.4	5:37	5:59
17	12.3	5:39	5:56
18	12.2	5:40	5:54
19	12.2	5:42	5:52
20	12.1	5:43	5:50
21	12.0	5:45	5:47
22	12.0	5:46	5:45
23	11.9	5:48	5:43
24	11.9	5:49	5:41
25	11.8	5:51	5:39
26	11.7	5:52	5:36
27	11.7	5:54	5:34
28	11.6	5:55	5:32
29	11.5	5:57	5:30
30	11.5	5:58	5:27

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.3 kWh/m².

For context, solar energy here swings from a low near 0.76 kWh/m² to a high of 5.56 kWh/m² in June across the year — September's 3.3 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)	4.0	3.9	3.9	3.8	3.8	3.7	3.7	3.7	3.6	3.6	3.5	3.5	3.4	3.4	3.4	3.3	3.3	3.2	3.2	3.1	3.1	3.0	3.0	2.9	2.9	2.8	2.8	2.7	2.7	2.6
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	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	4.0	Moderate
2	3.9	Moderate
3	3.9	Moderate
4	3.8	Moderate
5	3.8	Moderate
6	3.7	Moderate
7	3.7	Moderate
8	3.7	Moderate
9	3.6	Moderate
10	3.6	Moderate
11	3.5	Moderate
12	3.5	Moderate
13	3.4	Moderate
14	3.4	Moderate
15	3.4	Moderate
16	3.3	Moderate
17	3.3	Moderate
18	3.2	Moderate
19	3.2	Moderate
20	3.1	Moderate
21	3.1	Moderate
22	3.0	Moderate
23	3.0	Moderate
24	2.9	Moderate
25	2.9	Moderate
26	2.8	Moderate
27	2.8	Moderate
28	2.7	Moderate
29	2.7	Moderate
30	2.6	Moderate

Planning a trip in September

Is September a good time to visit Brno?

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

5.9

Sightseeing

4th-best month of the year

2.3

Beach & pool

4th-best month of the year

September is a reasonable time to visit Brno for sightseeing.

What to pack for Brno in September

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

In September, Brno sees daytime highs around 19°C and nights near 10°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Brno 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 Brno peaks around June 23 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	1	2	4	5	6	7	7	6	4	3	1	1
Level	Low	Low	Moderate	High	High	Very high	Very high	High	Moderate	Moderate	Low	Low

	UV index (midday)	Level
Jan	1	Low
Feb	2	Low
Mar	4	Moderate
Apr	5	High
May	6	High
Jun	7	Very high
Jul	7	Very high
Aug	6	High
Sep	4	Moderate
Oct	3	Moderate
Nov	1	Low
Dec	1	Low

Air quality in Brno 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 Brno is worst in June — around 19 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (December, 11 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Brno's WHO annual average of 15.4 µg/m³.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	14	14	18	18	18	19	17	17	15	13	12	11
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good	Good

	PM2.5 (µg/m³)	Level
Jan	14	Moderate
Feb	14	Moderate
Mar	18	Moderate
Apr	18	Moderate
May	18	Moderate
Jun	19	Moderate
Jul	17	Moderate
Aug	17	Moderate
Sep	15	Moderate
Oct	13	Moderate
Nov	12	Good
Dec	11	Good

Location & terrain

Where is Brno?

Brno sits at 49.2°N, 16.6°E, 226 m above sea level, in Czechia. The nearest listed city is Brno střed, 0.0 km away.

Topography around Brno

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

Within 3 km, the terrain around Brno has only modest variations in elevation — a maximum elevation change of 136 m around an average of 226 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 393 m; within 80 km, large variations in elevation — a maximum elevation change of 697 m.

The land around Brno is covered by artificial surfaces (64%) and trees (29%) within 3 km, trees (44%) and cropland (35%) within 16 km, and cropland (52%) and trees (33%) within 80 km.

3 km

136 m

artificial surfaces 64%

16 km

393 m

trees 44%

80 km

697 m

cropland 52%

treesgrasslandcroplandartificial surfaceswater

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

September weather nearby: Brno střed 0.0 km · Židenice 3.0 km · Žabovřesky 3.0 km · Královo Pole 4.0 km · Líšeň 6.0 km · Bystrc 7.0 km · Blansko 19 km · Vyškov 30 km

Czechia travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type C / E; 230 V · 50 Hz
Prices: ≈ 59% of US; price level, 2025
GDP per capita: $35,917; 2025
Happiness: 6.8 / 10; World Happiness, 2025
Safe drinking water: 98%; of population, 2024
Homicide rate: 0.8; per 100k, 2023
Road deaths: 5.9; per 100k/yr, 2019
Income group: High; World Bank
English: High; EF EPI 582
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 Brno (49.1952°, 16.608°, elevation 226 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).

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

	Clearer (%)	Cloudier (%)
1	49	51
2	49	51
3	48	52
4	48	52
5	47	53
6	47	53
7	47	53
8	47	53
9	46	54
10	45	55
11	45	55
12	45	55
13	45	55
14	44	56
15	45	55
16	44	56
17	43	57
18	43	57
19	43	57
20	43	57
21	43	57
22	42	58
23	42	58
24	42	58
25	41	59
26	41	59
27	41	59
28	40	60
29	40	60
30	39	61

	Rain chance (%)
1	34
2	34
3	34
4	34
5	34
6	34
7	34
8	34
9	34
10	34
11	34
12	33
13	33
14	32
15	32
16	32
17	32
18	32
19	31
20	31
21	30
22	30
23	29
24	29
25	29
26	29
27	29
28	30
29	30
30	31

	Dry (%)	Comfortable (%)	Humid (%)
1	72	22	6
2	73	22	5
3	74	21	5
4	76	20	4
5	77	20	3
6	77	20	3
7	79	19	2
8	79	19	2
9	80	18	2
10	81	18	1
11	82	17	1
12	82	17	1
13	83	16	1
14	84	15	1
15	85	14	1
16	87	13	0
17	87	13	0
18	88	12	0
19	89	11	0
20	90	10	0
21	91	9	0
22	92	8	0
23	93	7	0
24	93	7	0
25	94	6	0
26	94	6	0
27	95	5	0
28	95	5	0
29	95	5	0
30	95	5	0

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

	Clearer (%)	Cloudier (%)
1	49	51
2	49	51
3	48	52
4	48	52
5	47	53
6	47	53
7	47	53
8	47	53
9	46	54
10	45	55
11	45	55
12	45	55
13	45	55
14	44	56
15	45	55
16	44	56
17	43	57
18	43	57
19	43	57
20	43	57
21	43	57
22	42	58
23	42	58
24	42	58
25	41	59
26	41	59
27	41	59
28	40	60
29	40	60
30	39	61

	Rain chance (%)
1	34
2	34
3	34
4	34
5	34
6	34
7	34
8	34
9	34
10	34
11	34
12	33
13	33
14	32
15	32
16	32
17	32
18	32
19	31
20	31
21	30
22	30
23	29
24	29
25	29
26	29
27	29
28	30
29	30
30	31

	Dry (%)	Comfortable (%)	Humid (%)
1	72	22	6
2	73	22	5
3	74	21	5
4	76	20	4
5	77	20	3
6	77	20	3
7	79	19	2
8	79	19	2
9	80	18	2
10	81	18	1
11	82	17	1
12	82	17	1
13	83	16	1
14	84	15	1
15	85	14	1
16	87	13	0
17	87	13	0
18	88	12	0
19	89	11	0
20	90	10	0
21	91	9	0
22	92	8	0
23	93	7	0
24	93	7	0
25	94	6	0
26	94	6	0
27	95	5	0
28	95	5	0
29	95	5	0
30	95	5	0

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

	Clearer (%)	Cloudier (%)
1	49	51
2	49	51
3	48	52
4	48	52
5	47	53
6	47	53
7	47	53
8	47	53
9	46	54
10	45	55
11	45	55
12	45	55
13	45	55
14	44	56
15	45	55
16	44	56
17	43	57
18	43	57
19	43	57
20	43	57
21	43	57
22	42	58
23	42	58
24	42	58
25	41	59
26	41	59
27	41	59
28	40	60
29	40	60
30	39	61

	Rain chance (%)
1	34
2	34
3	34
4	34
5	34
6	34
7	34
8	34
9	34
10	34
11	34
12	33
13	33
14	32
15	32
16	32
17	32
18	32
19	31
20	31
21	30
22	30
23	29
24	29
25	29
26	29
27	29
28	30
29	30
30	31

	Dry (%)	Comfortable (%)	Humid (%)
1	72	22	6
2	73	22	5
3	74	21	5
4	76	20	4
5	77	20	3
6	77	20	3
7	79	19	2
8	79	19	2
9	80	18	2
10	81	18	1
11	82	17	1
12	82	17	1
13	83	16	1
14	84	15	1
15	85	14	1
16	87	13	0
17	87	13	0
18	88	12	0
19	89	11	0
20	90	10	0
21	91	9	0
22	92	8	0
23	93	7	0
24	93	7	0
25	94	6	0
26	94	6	0
27	95	5	0
28	95	5	0
29	95	5	0
30	95	5	0