Increasing crop species diversity within a region could improve agricultural sustainability, but knowledge of the spatiotemporal variation of crop species diversity and how this is related to pedo-climatic conditions is limited. In the current study, we used historical crop data records to quantify how crop species diversity is related to pedo-climatic conditions, and how crop diversity developed over time at the national and regional scale in Sweden between 1965 and 2019. Crop diversity was quantified using the exponent of the Shannon index. We found spatial differences across the country, with a significant increase in crop diversity from the north to the south, showing that there is a strong natural control of latitude and associated mean annual temperature on crop diversity in Sweden. Mean annual precipitation and soil texture had no significant relationship with crop diversity across Sweden. At the national level, crop diversity had no significant change over time. At the county level, our analyses revealed different temporal trends between counties. Crop diversity increased over time in certain counties, while in others no change or a decrease occurred. The temporal changes could not be explained by climate trends, and were likely influenced by socioeconomic factors. However, more than half of the counties showed an increase in crop diversity, suggesting that it is possible to increase crop diversity in Sweden. Our study shows that both natural and socioeconomic factors need to be considered to achieve an increase in crop diversity in the future.