Planning a trip to Trieste in September? You are in luck! The weather is generally good, with an average maximum temperature of +75°F and approximately 11 sunny days. Just be prepared for some rain, as there are usually around 10 rainy days and 152 mm of precipitation. Expect good weather and pack accordingly to enjoy the outdoors. Search flightsin one click on Avionero.
Average weather
☀️
+75°F
Avg. max. temperature
+43°F
Min.
+90°F
Max.
152 mm
Total precipitation
67%
Avg. humidity
1 m/s
Avg. wind
11 ☀️
Sunny Days
5 ⛅️
Cloudy
10 🌦
Rainy
Our opinion: Trieste has good weather in September.
Average temperature in Trieste in September
Here are the expected maximum, average and minimum temperatures in Trieste for September based on the historical data.
Last Year
Historical Data
Going from a maximum of +86°F during the day to a minimum of +63°F during the night, the temperature in September averages around +81°F.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +81°F to +81°F.
Is Trieste warm or cold in September?
Trieste is typically warm in September.
Maximum temperatures go down compared to the previous month from +84°F to +75°F. The minimum temperature also goes down from +68°F to +61°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in Trieste:
Water temperature in Trieste in September
Water in Trieste in September is Comfortable. It varies from +68°F to +79°F, with an average of +74°F.This is almost similar to the air temperature, which averages +75°F.
The water temperature in September is one of the warmest of the entire year:
The warmest water temperatures in Trieste are reached in August, when the average sea temperature rises to +77°F. The coldest water temperatures are in February, with an average of +49°F.
Can you swim in Trieste in September?
The water in Trieste in September is pretty comfortable (+74°F in average). Ideal for swimming, especially in outdoor pools and open water. Suitable for recreational and casual swimmers.
🦭
Cold
Below +61°F
🏄♂️
Fresh
61°F - 70°F
🏊
Comfortable
70°F - 77°F
👙
Warm
77°F - 82°F
🔥
Very warm
+82°C and up
Don’t forget a large beach towel or two for drying off.
Climate in Trieste in September
Trieste weather looks like this, on average, in September and the surrounding months.
August
September
October
Avg. temperature
+84°F
+75°F
+66°F
Min. temperature
+46°F
+43°F
+30°F
Max. temperature
+99°F
+90°F
+86°F
Rainfall
101 mm
152 mm
156 mm
Wind
1 m/s
1 m/s
2 m/s
Avg. water temperature
+77°F
+74°F
+66°F
Humidity
64%
67%
70%
Air pressure
1013 HPa
1015 HPa
1017 HPa
Sunny days
14
11
10
Cloudy days
4
5
6
Rainy days
9
10
13
Snowy days
0
0
0
September weather is still as good as in August.It’s getting colder in September. From +84°F in the day, the average maximum temperature lowers to +75°F.Prepare for more rain. Average rainfall goes from 101 mm to 152 mm.Humidity rises from 64% to 67%.The average wind speed doesn’t change much during September, staying around 1 m/s.The days becoming less sunny, going from 14 sunny days in August to 11 in September.
October brings much the same weather, it remains good.
Wind speed in Trieste in September based on historical data.
Last Year
Historical Data
The average wind speed is 2 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Trieste is gradually increasing during September, going from 1 m/s to 2 m/s over the course of the month.
Rain
Amount of rainfall in mm during September in Trieste based on historical data.
Last Year
Historical Data
Typically, there is a 33% chance of rain on an average day in September, with total rainfall of approximately 111 mm. The maximum amount of rainfall per day is around 38 mm, which is moderate rain.September is a pretty wet month with over 10 rainy days, so don’t forget to pack an umbrella, raincoat, and a pair of wellies.
September is one of the rainiest months in Trieste, here is a comparison with other months, total mm:
Trieste wettest month is November, where a typical day has a 43% chance of precipitation and 163 mm of rainfall per day. July, on the other hand, is the driest month with a mere 26% chance of precipitation and 72 mm of rainfall per day.
How was the weather last September in Trieste?
This is the weather in Trieste in September 2023:
1 September
🌧️
+81°F
2 September
☁️
+82°F
3 September
☁️
+83°F
4 September
☀️
+82°F
5 September
☀️
+80°F
6 September
☀️
+84°F
7 September
☀️
+84°F
8 September
☀️
+85°F
9 September
☀️
+86°F
10 September
☀️
+87°F
11 September
☀️
+86°F
12 September
☁️
+83°F
13 September
☁️
+81°F
14 September
☁️
+78°F
15 September
☀️
+80°F
16 September
☀️
+80°F
17 September
☁️
+79°F
18 September
☁️
+78°F
19 September
🌧️
+80°F
20 September
☀️
+80°F
21 September
🌧️
+75°F
22 September
🌧️
+79°F
23 September
🌧️
+74°F
24 September
☁️
+68°F
25 September
☀️
+75°F
26 September
☀️
+82°F
27 September
☀️
+82°F
28 September
☀️
+82°F
29 September
☀️
+82°F
30 September
☁️
+81°F
In September 2023 Trieste had 16 sunny days, 9 cloudy days, and 5 rainy days. The average maximum temperature was +81°F, with an absolute maximum of +86°F and a minimum of +68°F. The average humidity was 76%, with a maximum of 100% and a minimum of 48%. The average wind speed was 2 m/s, with a maximum of 8 m/s and a minimum of 0 m/s.
Are you planning a trip in September?
Climate Change Over the Years
This is how Trieste climate has changed over the last 43 years.
The climate in Trieste in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1980 (+63°F) and the highest in 2022 (+69°F). The driest year was 2003 with only 712 mm of rainfall, and the wettest year was 2019 with 2509 mm.
FAQ
Frequently asked questions about the weather in Trieste in September:
Is September a good time to visit Trieste?
September is a really good time to go to Trieste. The weather is nice so plan your packing around outdoor activities and exploring. Check out other good time to visit Trieste.
Can you sunbathe in Trieste in September?
September is warm in Trieste. You may enjoy some beach or pool time in the day, but pack something a tad warmer for the evening.
Can you swim in Trieste in September?
Yes, the water temperature in Trieste in September is considered moderate and enjoyable for most people, averaging around +74°F.
Is Trieste rainy in September?
Trieste is often rainy in September. You may get a bit damp when outside, so pack an umbrella, and maybe even a raincoat.
Is it sunny in Trieste in September?
The amount of sunny days in Trieste during September varies; prepare for a mix of clouds and sun.
For this page, we’ve looked at the typical weather in Trieste, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.