Triple digit heat is common in the desert Southwest and even parts of the South, but it's not every day, or even every year, that Portland, Oregon reaches 100°. But the Rose City hit the century mark on Sunday for the first time this summer. Portland officially hit 100° at 4:57pm Pacific Time on Sunday afternoon, according to the National Weather Service (NWS) office, making it the first 100° reading so far in 2018 there. For Portland, it was their first time at or above 100° since August 3rd, 2017. In 2010, 2011, 2013 and 2014 it didn't reach 100° or above in Portland. Portland averages only 12 days a year with a high of 90° or above, and since 1940, there have been over 30 years without an 100° or above reading. But there's good news for cool weather fans: A much more pleasant and less hot air mass is already moving in. An onshore flow will keep Portland and the Willamette Valley mainly in the low-to-mid 80s for the rest of the week, which is much closer to average for this time of year. Stay with WeatherNation for the latest on the heat across the Northwest. For WeatherNation: Meteorologist Chris Bianchi