Open Data Insights

Century of Fasnacht weather data challenges belief in divine intervention.

Published: March 2, 2026 · Period: 2026-03-02

Analysis of 100 years of weather data for Basel's Fasnacht reveals a clear warming trend and less frequent snowfall in recent decades, but high historical variability in temperature and precipitation challenges the playful belief in consistently favorable weather.
Century of Fasnacht weather data challenges belief in divine intervention.

Century of Fasnacht weather data challenges belief in divine intervention.

Photo: Azimronnie, Carnival de Basel, on Wikipedia Commons, licensed under CC BY-SA 4.0.

There is a saying in Basel: “God must be a Basel citizen.” It reflects the playful belief that the weather during Fasnacht is usually pleasant, as if higher powers were looking after the celebration. But is that really true? We analysed 100 years of weather data to find out.

During the past 100 years, Fasnacht was not observed 12 times due to the world wars and the COVID-19 pandemic. The weather for the reference year 2026 was warm. The average temperature was 11.4°C, with a minimum of 3.1°C and a maximum of 17.3°C. Total precipitation was 0.5 mm, with rain falling on one day. The average cloud cover, derived from one clear day, suggests partly cloudy conditions. This pleasant weather supports the hypothesis of divine intervention, but the rest of the analysis will examine whether this holds over a longer period.

Over the 100-year period, the long-term average temperature for Fasnacht is 2.8°C. The coldest year was 1956 with an average of -9.8°C, while the warmest was 2003 at 11.6°C. The data shows a clear warming trend, with recent decades being significantly milder than earlier ones. The reference year 2026, at 11.4°C, was well above the long-term average. Figure 1 illustrates the temperature trend over the last century, and Table 1 lists years with the most extreme weather phenomena.

The average total rainfall during Fasnacht over the century is 4.7 mm. Dry years, with zero precipitation, occurred in 43% of all observed years. The wettest year was 1970 with 24.3 mm of rain. No strong long-term trend in precipitation is evident. The long-term average cloud cover, inferred from clear days, indicates predominantly overcast conditions. These mixed findings suggest the popular belief in consistently good weather is only partially supported by the precipitation and cloudiness data.

Measurable snowfall occurred in 18 years over the century. The most significant snowfall was in 2006 with a maximum snow cover of 40 cm. Snow was more frequent in earlier decades, with a visible long-term decline in recent years. In conclusion, while recent Fasnachts have been warmer and less snowy, the historical data reveals high variability with many cold and wet years, statistically challenging the notion of consistently divine weather.

Table 1: Extreme Weather Record Years for the Carnival of Basel

Phenomenon	Year	Value
Maximum Average Temperature °C	2003	13.8
Maximumn Precipitation mm	1958	22.2
Maximum Snow Amount cm	2006	40.0
Maximum Temperature °C	2003	22.0
Minimum Average Temperature °C	1956	-14.2
Minimum Temperature °C	1956	-21.3

Figure 1: Temperature during the last 100 Years of Fasnacht

Figure 2: Precipitation during the Fasnacht of Basel in the last 100 Years

Data source: Tägliche Klimadaten der NBCN-Station Basel-Binningen

🤖 This text was generated with the assistance of AI. All quantitative statements are derived directly from the dataset listed under Data Source.

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Century of Fasnacht weather data challenges belief in divine intervention.

Table 1: Extreme Weather Record Years for the Carnival of Basel

Figure 1: Temperature during the last 100 Years of Fasnacht

Figure 2: Precipitation during the Fasnacht of Basel in the last 100 Years