In general, during June and July average temperatures are in the 60's to mid 70's. Temperatures in the fall are quite a bit cooler and average in the 50's-60’s. Temperatures can drop into the 30's and 40's at almost any time in Alaska. Keep in mind that Alaska has unpredictable weather...it is good to always come prepared. You will encounter some biting insects such as mosquitoes, no see-ums, and white sox, but typically a light coating of insect repellent is enough to keep them off. On the river, where there is usually a light breeze, you should hardly notice them. If the weather is perfect for bugs sometimes a head net is nice to have.