The dry season, roughly May to September, is the best time to visit, with less rain, lower humidity and easier sightseeing. The wet season, November to March, brings heavy downpours and localized flooding that worsen the already-tough traffic. Jakarta is hot and humid year-round, so pace outdoor activity and carry water.
Jakarta's traffic is dense, chaotic and among the worst in the region, and motorbikes weave unpredictably between lanes. Cross roads with great care, ideally at signals or footbridges, and factor long travel times into every plan. If riding a Gojek or Grab motorbike, always wear the provided helmet.
During the November–March rainy season, sudden downpours can flood streets and underpasses within minutes and paralyze traffic. Avoid low-lying areas during heavy rain, keep some schedule flexibility, and monitor local weather alerts. Flash flooding is a recurring seasonal hazard.
Pickpocketing and bag-snatching occur in crowded markets, on packed buses and at transit hubs and festivals. Keep phones and wallets secure and out of sight, wear bags across the body in front of you, and stay alert in dense crowds. Violent crime against tourists is rare, but opportunistic theft is not.