Statistics

Statistics by country and year

Yearly summaries computed from the daily readings of every station: how many station-days were spent below the low-water level (LDC) or above the high-water level (HDC) — as a count and as a share of the station-days with thresholds. Useful for agriculture (irrigation seasons with low water) and navigation (days with restricted draught).

Agriculture: station-days below LDC mark the low-water periods when irrigation intakes and water availability are under pressure.
Navigation: days below LDC mean draught restrictions on that sector; days above HDC mean suspended traffic.

Daily data from 1879 to 6 November 2026

Download this tab’s data (CSV)

LDC: Low-water mark. The river stays above it on 94 of 100 ice-free days; below it, ships cannot sail fully loaded.
HDC: High-water mark. The river exceeds it on 1 day in 100; above it, navigation can be suspended.
Station-days: One station-day is one station measured for one day: 13 stations over 10 days make 130 station-days. It shows how widely and how long something lasted.

Irrigation season 1971: Bulgaria spent the longest below LDC, 2 % of days

Irrigation season (April–September)

Station-days below LDC in the irrigation season, by country and year, against the average of the other years; the longest uninterrupted spells below LDC.

5%1%

2%5%

1971Meanbelow LDC in season

Irrigation season (April–September) 1971
countries	station-days in season	below LDC in season	%	vs. average
Austria	183	10	5%	+4 pp
Hungary	3,477	0	0%	-2 pp
Croatia	549	0	0%	-1 pp
Bulgaria	1,098	21	2%	-3 pp

Longest spells below LDC

Uninterrupted periods of at least 5 days below LDC, by station.

Longest spells below LDC
Station	countries	From	To	days
Ybbs	Austria	1971-12-29	1972-04-02	96
Oryahovo	Bulgaria	1971-10-16	1971-11-27	43
Ybbs	Austria	1971-10-17	1971-11-18	33
Óbuda	Hungary	1971-10-27	1971-11-21	26
Silistra	Bulgaria	1971-11-05	1971-11-25	21
Ybbs	Austria	1971-11-21	1971-12-11	21
Vukovar	Croatia	1971-10-29	1971-11-16	19
Vác	Hungary	1971-10-28	1971-11-13	17
Ybbs	Austria	1971-03-01	1971-03-16	16
Budapest	Hungary	1971-10-29	1971-11-13	16

The daily series uses the first reading of each day.