January in Lewisville averages a daily high of 14.1°C with nights around 0.7°C. Expect roughly 6.7 wet days totalling 64mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Lewisville is March–April.
Based on GRAPEVINE DAM, TX US (12.1km), 1995–2024. 23 years of January data.