The best months to visit Luxembourg are July and September. See monthly temperatures, rainfall and rain days (1991–2020 averages) to plan your trip.
Average daytime high and monthly rainfall in Luxembourg: January 4°C / 69mm; February 9°C / 59mm; March 12°C / 61mm; April 13°C / 53mm; May 18°C / 68mm; June 20°C / 63mm; July 23°C / 60mm; August 25°C / 64mm; September 19°C / 61mm; October 15°C / 69mm; November 8°C / 70mm; December 5°C / 85mm.