, with cold winters and warm summers.
The city is located in the Karst hills, at 530 meters (1,700 feet) above sea level, and 30 km (18 mi) north-east of Trieste.
In winter, the bora, the cold wind from the plains of Eastern Europe, can blow. During cold spells, the temperature can drop to -20 °C (-4 °F) or even below. The cold record is -26.4 °C (-15.5 °F), set in January 1968.
In summer, temperatures are pleasant and are suitable for outdoor activities, although there can be rains and thunderstorms, even strong.
Sometimes there can be hot periods, although less so than in the plains. The heat record is 36.4 °C (97.5 °F), set in August 2013.
to visit Postojna runs from mid-May to mid-September, since it is the warmest and sunniest period of the year. Sometimes, it can be hot in July and August, while in other circumstances, nights can be cool or even a little cold even in these months, so it can be useful to bring a sweatshirt or sweater and a light jacket for the evening.
. Here are the average temperatures.
January, the coldest month of the year, is generally a cold month. The average temperature is of
0.7 °C, with a minimum of
-2.8 °C and a maximum of
4.1 °C.
On the coldest nights of the month, the temperature usually drops to around
-11 °C. However, it dropped to
-16.8 °C in January 2000.
On the warmest days of the month, the temperature usually reaches around
11.5 °C. However, it reached
15.3 °C in January 2013.
Precipitation amounts to
90 mm, distributed over 8 days.
The day lasts on average 9 hours and 5 minutes.
There are on average 3 hours of sunshine per day. So, the sun shines 33% of the time.
The average humidity is 83%. Hence, the air is normally humid.
February is generally a cold month. The average temperature is of
1.7 °C, with a minimum of
-2.6 °C and a maximum of
6.1 °C.
On the coldest nights of the month, the temperature usually drops to around
-10.5 °C. However, it dropped to
-15.5 °C in February 2018.
On the warmest days of the month, the temperature usually reaches around
13.5 °C. However, it reached
21 °C in February 1998.
Precipitation amounts to
105 mm, distributed over 8 days.
The day lasts on average 10 hours and 25 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 80%. Hence, the air is normally humid.
March is generally a quite cold month. The average temperature is of
5.4 °C, with a minimum of
0.4 °C and a maximum of
10.3 °C.
On the coldest nights of the month, the temperature usually drops to around
-7 °C. However, it dropped to
-19.5 °C in March 2005.
On the warmest days of the month, the temperature usually reaches around
18 °C. However, it reached
22.2 °C in March 2019.
Precipitation amounts to
100 mm, distributed over 8 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 42% of the time.
The average humidity is 78%. Hence, the air is normally humid.
April is generally a mild month. The average temperature is of
9.2 °C, with a minimum of
3.7 °C and a maximum of
14.7 °C.
On the coldest nights of the month, the temperature usually drops to around
-3 °C. However, it dropped to
-9.2 °C in April 2003.
On the warmest days of the month, the temperature usually reaches around
22 °C. However, it reached
27.9 °C in April 2012.
Precipitation amounts to
115 mm, distributed over 11 days.
The day lasts on average 13 hours and 35 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 43% of the time.
The average humidity is 77%. Hence, the air is normally humid.
May is generally a mild month. The average temperature is of
13.6 °C, with a minimum of
7.7 °C and a maximum of
19.5 °C.
On the coldest nights of the month, the temperature usually drops to around
1.5 °C. However, it dropped to
-1.7 °C in May 2019.
On the warmest days of the month, the temperature usually reaches around
26.5 °C. However, it reached
31.6 °C in May 2009.
Precipitation amounts to
130 mm, distributed over 11 days.
The day lasts on average 15 hours and 0 minutes. So the days are long.
There are on average 7 hours of sunshine per day. So, the sun shines 45% of the time.
The average humidity is 77%. Hence, the air is normally humid.
June is generally a very mild month. The average temperature is of
17.5 °C, with a minimum of
11.4 °C and a maximum of
23.6 °C.
On the coldest nights of the month, the temperature usually drops to around
6 °C. However, it dropped to
1.6 °C in June 1994.
On the warmest days of the month, the temperature usually reaches around
30 °C. However, it reached
34.6 °C in June 2019.
Precipitation amounts to
120 mm, distributed over 10 days.
The day lasts on average 15 hours and 40 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 7.5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 79%. Hence, the air is normally humid.
July is generally a warm month. The average temperature is of
19.5 °C, with a minimum of
13 °C and a maximum of
26 °C.
On the coldest nights of the month, the temperature usually drops to around
7.5 °C. However, it dropped to
3.6 °C in July 1993.
On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
35 °C in July 2006.
Precipitation amounts to
100 mm, distributed over 8 days.
The day lasts on average 15 hours and 20 minutes. So the days are long.
There are on average 8.5 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 77%. Hence, the air is normally humid.
August, the warmest month of the year, is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19.6 °C, with a minimum of
13 °C and a maximum of
26.1 °C.
On the coldest nights of the month, the temperature usually drops to around
6.5 °C. However, it dropped to
3 °C in August 1995.
On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
36.4 °C in August 2013.
Precipitation amounts to
110 mm, distributed over 8 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 8.5 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 79%. Hence, the air is normally humid.
September is generally a very mild month. The average temperature is of
15 °C, with a minimum of
9.6 °C and a maximum of
20.3 °C.
On the coldest nights of the month, the temperature usually drops to around
3 °C. However, it dropped to
-2 °C in September 1995.
On the warmest days of the month, the temperature usually reaches around
26 °C. However, it reached
31.2 °C in September 2011.
Precipitation amounts to
160 mm, distributed over 10 days.
The day lasts on average 12 hours and 30 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 82%. Hence, the air is normally humid.
October is generally a mild month. The average temperature is of
10.7 °C, with a minimum of
6.5 °C and a maximum of
15 °C.
On the coldest nights of the month, the temperature usually drops to around
-2 °C. However, it dropped to
-9.6 °C in October 2003.
On the warmest days of the month, the temperature usually reaches around
21.5 °C. However, it reached
25.9 °C in October 2017.
Precipitation amounts to
165 mm, distributed over 11 days.
The day lasts on average 10 hours and 55 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 40% of the time.
The average humidity is 83%. Hence, the air is normally humid.
November is generally a quite cold month. The average temperature is of
6.1 °C, with a minimum of
2.7 °C and a maximum of
9.4 °C.
On the coldest nights of the month, the temperature usually drops to around
-6.5 °C. However, it dropped to
-15.6 °C in November 1999.
On the warmest days of the month, the temperature usually reaches around
16.5 °C. However, it reached
21.8 °C in November 2015.
Precipitation amounts to
185 mm, distributed over 12 days.
The day lasts on average 9 hours and 30 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 28% of the time.
The average humidity is 84%. Hence, the air is normally humid.
December is generally a cold month. The average temperature is of
1.4 °C, with a minimum of
-2 °C and a maximum of
4.9 °C.
On the coldest nights of the month, the temperature usually drops to around
-11.5 °C. However, it dropped to
-19 °C in December 2010.
On the warmest days of the month, the temperature usually reaches around
12 °C. However, it reached
15.5 °C in December 2016.
Precipitation amounts to
140 mm, distributed over 10 days.
The day lasts on average 8 hours and 40 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 2.5 hours of sunshine per day. So, the sun shines 30% of the time.
The average humidity is 84%. Hence, the air is normally humid.