Pack or skip
Insect repellent for Tokyo in September
Verdict
Pack it
Warm (80°F) plus 12 rainy days = mosquito conditions.
Why
Tokyo in September averages highs of 80°F, lows of 68°F, 12 rainy days.
That climate means insect repellent earns its space in the bag. Warm (80°F) plus 12 rainy days = mosquito conditions.