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Istria weather in September

Weather in Istria: September

Average day temperature: 74.0°F
Average night temperature: 66.4°F
Sea water temperature: 73.8°F
Number of sunny days: 18 days
Day length: 11.8 - 13.3 hours
Number of rainy days: 6 days
Precipitation totals: 3.6 in.

Air temperature in September, °F

Show year:
2026
2025
2024

The highest day temperature during September of 2026 was 80°F. At the same time the lowest night temperature was 61°F. Daily and nightly averages during September were 73.8°F and 69.3°F.

Sea water temperature in Istria in September, °F

Show year:
2026
2025
2024

The average sea water temperature in September of 2026 was 76.6°F. The highest and lowest sea temperatures during the month were 80.4°F and 72.5°F.

Sunny, partly cloudy and cloudy days

Mostly all days in September are sunny but cloudy days are also possible.

Precipitation total in September, in.

Precipitation total value in Istria in September is 3.5 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 6.8 mph

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 8.3.

Best time for vacation in Istria

Sunniest months:
August 24 days
July 23 days
June 21 days
Warmest months:
August 82.2 °F
July 81.3 °F
June 76.6 °F
Warmest sea temp:
August 78.2 °F
July 77.6 °F
September 73.8 °F
Coldest months:
January 47.5 °F
February 49.2 °F
December 50.5 °F
Rainiest months:
November 6 days
September 6 days
May 5 days
Windiest months:
February 8.2 mph
November 8.1 mph
March 7.9 mph

Istria on a weather map

Istria
+68°F
SE 7 mph
Feels like: +68°F
Precip.: 2%
Places in Croatia:
Name
°F
+73°F
+73°F
+72°F
+73°F
+70°F
+68°F
+79°F
+77°F
+70°F
+68°F
+75°F
+72°F
+70°F
+77°F
+70°F
24 Hours Forecast
Istria
Local time: 15:51
October 04, sunday
1800
70°F
SE
5 mph
2100
66°F
SW
5 mph
October 05, monday
0000
64°F
SW
6 mph
0300
64°F
SW
5 mph
0600
64°F
SW
4 mph
0900
64°F
SW
3 mph
1200
68°F
S
4 mph
1500
68°F
S
6 mph

Best place for vacation:

Units of measurement: °C / °F