Pack or skip
Insect repellent for Seattle in September
Verdict
Pack it
Warm (70°F) plus 7 rainy days = mosquito conditions.
Why
Seattle in September averages highs of 70°F, lows of 52°F, 7 rainy days.
That climate means insect repellent earns its space in the bag. Warm (70°F) plus 7 rainy days = mosquito conditions.