Weather in Trieste for September 2026
In general, the average temperature in Trieste at the beginning of September is 26.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.3 °C by the end of September.
The climate of Trieste in September is notably wet, with an average of 15 rainy days, and a total of 114.5 mm of precipitation.
Is September a good time to visit Trieste? check out the best time to travel to Trieste page.
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Trieste Weather September
Temperatures trend during September in Trieste
September weather in Trieste day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Partly cloudy | 27° /17° | 0.1 mm | 7 | |
| 2 Sept. |  Sunny | 26° /17° | 4.3 mm | 6 | |
| 3 Sept. | Sunny | 27° /17° | 0.8 mm | 6 | |
| 4 Sept. | Partly cloudy | 27° /17° | 0.1 mm | 7 | |
| 5 Sept. |  Patchy rain possible | 26° /17° | 2.8 mm | 6 | |
| 6 Sept. | Sunny | 26° /16° | 2.5 mm | 6 | |
| 7 Sept. | Sunny | 27° /16° | 0 mm | 7 | |
| 8 Sept. | Sunny | 27° /15° | 2.5 mm | 6 | |
| 9 Sept. | Sunny | 25° /16° | 10.9 mm | 6 | |
| 10 Sept. | Sunny | 25° /16° | 16.4 mm | 6 | |
| 11 Sept. | Sunny | 25° /16° | 5.2 mm | 6 | |
| 12 Sept. | Partly cloudy | 23° /14° | 20.4 mm | 5 | |
| 13 Sept. | Sunny | 22° /14° | 0.3 mm | 5 | |
| 14 Sept. | Partly cloudy | 22° /14° | 5.6 mm | 5 | |
| 15 Sept. | Partly cloudy | 22° /14° | 0 mm | 6 | |
| 16 Sept. | Partly cloudy | 23° /13° | 5.6 mm | 6 | |
| 17 Sept. | Partly cloudy | 21° /13° | 0.1 mm | 5 | |
| 18 Sept. |  Cloudy | 24° /14° | 0 mm | 6 | |
| 19 Sept. | Light rain shower | 24° /16° | 4.6 mm | 6 | |
| 20 Sept. | Light rain shower | 25° /15° | 1.2 mm | 6 | |
| 21 Sept. | Sunny | 24° /15° | 1.6 mm | 6 | |
| 22 Sept. |  Moderate or heavy rain shower | 24° /15° | 11.9 mm | 6 | |
| 23 Sept. | Patchy rain possible | 21° /15° | 4.1 mm | 5 | |
| 24 Sept. | Light rain shower | 20° /14° | 14.8 mm | 5 | |
| 25 Sept. | Partly cloudy | 21° /12° | 6 mm | 5 | |
| 26 Sept. | Sunny | 21° /13° | 1.2 mm | 5 | |
| 27 Sept. | Sunny | 23° /15° | 3.3 mm | 6 | |
| 28 Sept. | Patchy rain possible | 23° /13° | 0.9 mm | 6 | |
| 29 Sept. |  Overcast | 21° /12° | 0.1 mm | 5 | |
| 30 Sept. | Partly cloudy | 20° /11° | 0.4 mm | 5 | |
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Trieste weather in September vs August vs October
| August | September | October | |
|---|---|---|---|
| Weather | Sunny | Patchy rain possible | Patchy rain possible |
| Temperatures | 29°/20° | 24°/15° | 19°/13° |
| Rainfall | 167 mm | 114 mm | 171 mm |
| Wind | 12 km/h | 14 km/h | 14.3 km/h |
| Humidity | 63% | 68% | 78% |
| Rainy days | 13 days | 15 days | 21 days |
| Dry days | 18 days | 15 days | 10 days |
Planning a trip to Trieste? Discover the best time to visit
Trieste in September - FAQ
What to pack to Trieste in September?
As you prepare for your trip to Trieste in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in Trieste, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Layered Clothing: Light sweaters, long-sleeve shirts, light jackets, and comfortable pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Umbrellas/Raincoats: For rainy days
September rainfall patterns in Trieste
UV exposure in Trieste during September
Quick links
Where is Trieste?Get accurate weather forecasts for Trieste, located at latitude 45.65 and longitude 13.777. Stay updated with localized weather information tailored for Trieste.