Improvements make Portland's MAX trains more resilient in face of extreme heat

(JUNE 23, 2025) TriMet is the public transportation agency for the Portland metropolitan area. It provides bus, light rail (MAX), and commuter rail (WES) service. 

TriMet getting ready for the summer heat, which has become more common and intense in Oregon. Since 2020, Portland has seen 100-degree temperatures 20 times, all during the summer months. To handle this, TriMet has made improvements to MAX and WES trains so they can run more reliably in hot weather. Even with these upgrades, riders should plan for extra travel time during heat waves and check for updates at trimet.org/alerts.

One issue in extreme heat is that metal expands, which can cause overhead wires to sag and rails to bend. To prevent problems, TriMet slows MAX trains to 35 mph and WES trains to 40 mph when it’s 100°F or hotter. These slowdowns can cause delays—up to 30 minutes for MAX and 10 minutes for WES. If it reaches 105°F, WES service stops completely. MAX may be suspended at 110°F. If that happens, buses and shuttle service will be provided.

All TriMet vehicles have air conditioning, but not all stops have shade. Riders should prepare by bringing water, wearing sunscreen, and carrying umbrellas or portable fans. Drinks are allowed on board in closed containers like bottles or travel mugs. Personal shade items are fine as long as they don’t block walkways.