Benchmarked strictly across TripTiming's 5 empirical pillars: Crowds, Weather, Vibes, Prices, and Safety.
Prague emerges as the optimal September destination with an overall TripTiming Index of 60/100 vs 58/100 for Vienna (+2 point advantage). Prague captures optimal environmental comfort with 17°C daytime feels-like temperatures and 52% rain probability, compared to 18°C in Vienna. This is reinforced by lower lodging rates (~$198/night vs ~$239/night, saving ~$287 over 7 nights). While Vienna retains an edge in Space & Crowds (65/100 vs 57/100), Prague's commanding performance in Weather Comfort secures the overall September recommendation.