PORTLAND, Ore. (KOIN) — Officials are warning MAX and WES riders about transportation delays ahead of potentially record-setting triple-digit heat this weekend.

TriMet said MAX Orange and Green lines may see delays once temperatures hit 90 degrees, and all MAX lines and Wes will be delayed once the thermostat hits 100 degrees. Furthermore, WES will be replaced by shuttle buses starting at 105 degrees.

Once it hits 90 degrees, Orange Line MAX trains between Tillikum Crossing and SE Park Ave Station and Green Line trains between Gateway Transit Center and Clackamas will reduce speeds by 10 mph in higher speed area; riders should expect 15 minute delays, according to TriMet.

When temperatures soar above 100 degrees, all MAX lines will be reduced to speeds of no more than 35 mph, resulting in delays of up to 30 minutes.

As for WES, trains will be reduced to 40 mph when temperatures hit 100 degrees, resulting in 20-minute delays. When temps hit 105 degrees, train service will be suspended and will be replaced by shuttle buses on the line. “Expect major delays,” according to TriMet.

Burn bans have been announced in Multnomah and Clackamas counties ahead of this weekend’s Excessive Heat Warning, which starts Friday and ends Monday. Friday’s temperatures are slated to be in the high 90s, while hitting triple-digits on Saturday, Sunday and Monday.