September · Italy
Best time to visit Trieste in September Weather, crowds & prices
Weather in Trieste in September
Average temperature 20°C, 172 mm of rain, about 13 days with 6+ hours of sunshine and 74% humidity — based on the five most recent complete years of ERA5 data (2021–2025).
September score
6.5/10
Ranked #6 of 12 months
- Avg temp
- 20°C
- Rainfall
- 172 mm
- Humidity
- 74%
- Days with 6h+ sun
- 13
- Crowd Density
- Moderate Crowds
- Average Expenses
- $$ · Moderate Cost ($$)
September in Trieste scores 6.5/10 for sightseeing and cultural travel - an above-average month (#6 of 12). Expect around 20°C, 172 mm of rain, and roughly 13 days with 6+ hours of sunshine this month.
Trieste faces the Adriatic with Habsburg cafés, a grand piazza on the water, and a Mitteleuropean literary past. Best window: April-June and September-October.
September in Trieste: mixed conditions, plan around the weather
September averages 20°C (67°F) — pleasant for mornings and evenings on foot in the city, with a midday break when the sun is strongest.
At 172 mm this is a genuinely wet month: about 13 days with 6+ hours of sunshine in total, and outdoor plans need an indoor fallback.
It scores 6.5/10 here, 6th of 12 months, against 8.6/10 in the destination's best month.
Pack light clothing, a hat and real sun protection, a proper rain shell rather than an umbrella.
Plan for mid-season pricing, with crowds are moderate.
Flexible dates? June scores 2.1 points higher here — enough to change the trip.
Frequently asked
- What is the weather like in Trieste in September?
- In September, Trieste averages 20°C, 172 mm of rain, and about 13 days with 6+ hours of sunshine. Its climate-comfort score is 6.5/10.
- Is September a good time to visit Trieste?
- September earns a 6.5/10 climate-comfort score. Use the year-round chart to weigh the weather against your budget and crowd preferences.
- How much does it rain in Trieste in September?
- Expect about 172 mm of rain in September. Average humidity is 74% and there are about 13 days with 6+ hours of sunshine.
Curated in Trieste
Tickets & experiences
Things to do in Trieste
Trieste, Italy. Live activities and tours from GetYourGuide, matched to this destination.