May in Harlow averages a daily high of 16.8°C with nights around 7.4°C. Expect roughly 11.6 wet days totalling 50.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Harlow is June–September.
Based on ROTHAMSTED, UK (17.3km), 1995–2024. 30 years of May data.