Breathing in Zadar

44.1194°N · 15.2314°E · 2 m a.s.l.

Saturday, 3 October

Hard to breathe

The air is saturated with moisture and barely ventilates. The kind of day when a breath feels thick.

Temperature: 25.2 °C max
Feels like: 24.0 °C max
Wet bulb: 16.6 °C max
Daytime wind: 9 km/h

Mixing layer

the height air actually mixes up to

9006754502250 m

000306091215182123

This is the ceiling over the town: everything that evaporates or is emitted below gets smeared through exactly this layer. The dashed line is 400 m, under which daytime mixing counts as stagnant. At night the layer always collapses — that is normal, not a signal.

Three factors

the day's verdict is the worst of the three

Water vapour

dry

8.3°C dew point

1619

How much water the air holds. Above 19 °C sweat stops evaporating, and the body sheds heat almost only by breathing.

26.094.10

Ground-level ozone

elevated

100µg/m³ hourly max

100120

A direct bronchial irritant, formed photochemically on clear windless days. The WHO reference is 100 µg/m³.

26.094.10

Ventilation

stagnant

359m, mean 10:00–20:00

400800

Daytime mixing depth. The lower the ceiling, the higher the concentration of everything below it.

26.094.10

Windows of the day

when to go out, and when to sit it out

0003060912151821

good moderate hard each hour takes the worse of two: dew point or ozone

Why today in particular

9 days hour by hour · the shaded band is today

Dew point

°C

20.010.00.0

Ozone

µg/m³

120600

Mixing layer

240012000

26.0927.0928.0929.0930.091.102.103.104.10

Three weeks

21 days

Temperature

°C

302010

Precipitation

mm per day

100

13.0917.0921.0925.0929.093.10

min–max range daily mean precipitation

All measurements

°C · mm · h · km/h · % · hPa · MJ/m²

Date	Tmax	Tmin	Tmean	Feels	Precip	Prec.h	Wind	Gusts	Humid	Press	Cloud	Radiat	ET₀	Dir.	Sun
13.09	27.4	15.5	21.4	27.0	0.0	0	21	43	60	1020.5	18	19.9	4.5	N	12.0
14.09	27.8	17.5	22.6	28.3	0.1	1	20	40	65	1019.6	49	18.0	4.1	N	12.0
15.09	28.4	16.3	22.1	28.9	0.0	0	22	46	66	1018.9	9	19.6	4.3	NW	12.0
16.09	28.0	15.9	21.8	28.2	0.0	0	14	31	65	1015.3	7	19.5	4.0	S	12.0
17.09	27.8	17.7	22.2	30.4	2.0	4	17	37	71	1013.9	46	15.9	3.6	SE	10.6
18.09	27.8	18.3	22.9	29.1	2.8	7	12	28	75	1014.6	65	16.9	3.3	W	11.5
19.09	27.8	18.6	22.5	29.4	8.7	6	13	31	76	1019.8	52	16.2	3.1	E	11.7
20.09	27.8	17.7	22.6	29.2	0.0	0	19	38	72	1021.8	28	18.1	3.7	NW	11.9
21.09	28.3	18.4	23.1	29.3	0.0	0	12	23	63	1019.3	63	15.3	3.5	NE	11.0
22.09	23.8	14.9	18.7	22.3	0.0	0	16	36	48	1020.9	2	18.6	3.8	NE	11.9
23.09	21.5	11.6	17.0	19.7	0.0	0	18	38	56	1023.9	2	18.3	3.6	NW	11.8
24.09	23.4	12.6	18.3	23.1	5.8	1	10	24	66	1021.0	71	16.4	3.2	SE	9.9
25.09	21.4	13.7	17.5	20.0	7.5	4	14	25	65	1019.6	23	17.4	3.2	N	11.8
26.09	24.0	11.7	17.5	22.2	0.0	0	20	39	65	1021.7	22	17.7	3.5	N	11.7
27.09	25.5	11.4	18.2	24.2	0.0	0	20	38	66	1022.3	8	17.5	3.6	NW	11.7
28.09	25.3	13.2	19.1	24.9	0.0	0	16	34	68	1022.0	6	17.1	3.4	NW	11.6
29.09	27.8	13.1	19.7	26.7	0.0	0	17	35	62	1023.6	3	17.4	3.4	SE	11.5
30.09	27.2	13.3	19.9	25.5	0.0	0	16	35	61	1024.3	0	17.2	3.8	NW	11.4
1.10	26.0	14.2	19.6	25.5	0.0	0	17	35	66	1023.6	5	16.6	3.5	NW	11.3
2.10	26.8	12.1	18.8	25.0	0.0	0	16	31	60	1026.7	47	15.7	3.4	N	11.0
3.10	24.2	11.3	17.6	22.4	0.0	0	13	28	63	1027.9	7	16.9	3.3	W	11.1

How the verdict is computed

Dew point, mean 10:00–20:00: under 16 dry · 16–19 humid · from 19 muggy.
Ozone, hourly maximum: under 100 low · 100–120 elevated · from 120 high (µg/m³; the WHO reference of 100 is an 8-hour mean).
Mixing layer, mean 10:00–20:00: under 400 stagnant · 400–800 moderate · from 800 good.
The day's verdict is the worst of the three. The hourly strip takes the worse of the first two: mixing depth collapses every night by definition, so hourly it says nothing.

Where the data comes from, and what it cannot know

Open-Meteo: ERA5 reanalysis for the daily series, the CAMS model for air composition, the forecast model for hourly detail. No key, CC BY 4.0.
Every day in the table comes from the ERA5 reanalysis.
This is a model in a grid cell, not a station in the yard: it does not see street microclimate, traffic under the window, or how well a flat is aired.
The composite score is our own, not an official air-quality index. The thresholds are stated above precisely so they can be checked.
If breathlessness is severe, persists at rest, or has appeared for the first time — that is for a doctor, not for a chart. Ozone peaks are a known trigger of latent asthma.