January in Harlingen averages a daily high of 21.5°C with nights around 9.9°C. Expect roughly 7.1 wet days totalling 26.8mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Harlingen is November–March.
Based on HARLINGEN, TX US (2.7km), 1995–2024. 25 years of January data.