In 2024, Basel-Stadt recorded 811 marriages, marking it as the year with the fewest marriages since 1979. This recent figure is part of a declining trend, as 2023 and 2022 also ranked among the three lowest years for marriages, with 830 and 843 marriages respectively. In contrast, the peak year for marriages in Basel-Stadt was 1991, with 1,365 marriages. The average age of brides in 2024 was 34.7 years, while grooms averaged 37.5 years. The youngest bride was 18, and the oldest was 84, while grooms ranged from 19 to 90 years old. The average age difference between couples was 2.8 years, with a maximum age difference of 40 years. Historically, the youngest recorded bride was 16, and the oldest groom was 95, with the largest age difference being 57 years when the man was older.

Examining long-term trends from 1979 to the present, there is a noticeable decline in the number of marriages in Basel-Stadt. The early 1980s saw higher numbers, with 1,040 marriages in 1979 and peaking in 1991. Since then, the numbers have generally decreased, with occasional fluctuations. The average age at marriage has increased over the decades. In 1979, the average age for brides was 27.9, and for grooms, it was 31.0. By 2024, these averages had risen to 34.7 for brides and 37.5 for grooms, indicating a trend toward later marriages.

The nationality patterns of marriages have also shifted significantly. In 1979, Swiss-Swiss marriages dominated, accounting for 68.9% of all marriages. Over time, this share has decreased, reaching 29.3% in 2023. Meanwhile, marriages involving at least one non-Swiss partner have become more common, reflecting broader demographic changes in Basel-Stadt.

Seasonality in marriages shows consistent patterns, with peaks typically occurring in the warmer months. According to the data, August and September have historically been the most popular months for weddings, averaging 122.7 and 118.5 marriages, respectively. This pattern is visible in the heatmap of marriages by month and year, which illustrates stable peaks in June and September until the late 1990s. However, the seasonality has become less pronounced in recent years, possibly due to changing social norms and preferences.

In summary, Basel-Stadt has experienced a long-term decline in the number of marriages, accompanied by an increase in the average age at marriage and a shift towards more diverse nationality combinations among couples. The seasonal pattern of marriages remains, albeit with some changes over time. These insights highlight the evolving nature of marriage in Basel-Stadt over the past decades.