GRAPH. Use this monthly calendar to view weather averages, such as average temperature 14 days ahead of today, as well as the historical weather patterns over. Van Alstyne Weather History for the Previous 24 Hours Show weather for: Previous 24 hours September 22, 2023 September 21, 2023 September 20, 2023 September 19, 2023 September 18, 2023 September 17, 2023 September 16, 2023 September 15, 2023 September 14, 2023 September 13, 2023 September 12, 2023 September 11, 2023 September 10, 2023 September.