Average Weather during July in Juneau (Alaska), United States of America. Be prepared July is also the hottest month. The amount of rain in July is high with an average of 106mm (4.2in). Find out when the sun will rise and set for your Alaska trip dates to Juneau in July. Here you can find all information about the weather in Juneau in July: >>Overview: Juneau Weather and Climate in July >>Juneau weather by month // weather averages The July weather guide for Juneau, Alaska shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Eta to recharge over warm waters, then threaten Cuba and Florida. Get the monthly weather forecast for Juneau, AK, including daily high/low, historical averages, to help you plan ahead. Find out more about our data sources . The average minimum temperature (usually the minimum temperature is noted during the night) in Juneau in July is 8.0°C (46.4°F). Print out … Juneau Weather and Climate in July Are you planning a holiday with hopefully nice weather in Juneau in July 2021? Alaska > Juneau > July. Get the monthly weather forecast for Juneau, AK, including daily high/low, historical averages, to help you plan ahead.