Avignon: Annual Weather Averages. July is the hottest month in Avignon with an average temperature of 24°C (75°F) and the coldest is January at 6°C (43°F) with the most daily sunshine hours at 13 in July.The wettest month is September with an average of 65.8mm of rain.vignon: Annual Weather Averages. July is the hottest month in Avignon with an average temperature of 24°C (75°F) and the coldest is January at 6°C (43°F) with the most daily sunshine hours at 13 in July.