Pack or skip
Insect repellent for Portland in September
Verdict
Pack it
Warm (73°F) plus 6 rainy days = mosquito conditions.
Why
Portland in September averages highs of 73°F, lows of 53°F, 6 rainy days.
That climate means insect repellent earns its space in the bag. Warm (73°F) plus 6 rainy days = mosquito conditions.