Portland, CO climate
Portland has cold, snowy winters and pleasant summers, with very little rain. A typical July afternoon reaches 80°, a January night drops to 13°, and about 126 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Portland feels like
Winter
Spring
Summer
Fall
Portland weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 13° | 1.5" | 22.4" | 8 | 30 | 18° – 31° |
| February | 39° | 15° | 1.4" | 19.6" | 8 | 29 | 22° – 34° |
| March | 47° | 22° | 1.7" | 23.8" | 9 | 29 | 29° – 39° |
| April | 54° | 28° | 1.8" | 14.6" | 10 | 12 | 37° – 47° |
| May | 64° | 36° | 1.6" | 3.6" | 7 | 2 | 45° – 55° |
| June | 76° | 44° | 0.9" | 0.1" | 6 | 0 | 55° – 64° |
| July | 80° | 51° | 2.1" | 0 | 10 | 0 | 61° – 68° |
| August | 77° | 49° | 2.2" | 0 | 15 | 0 | 61° – 67° |
| September | 70° | 42° | 1.9" | 0.5" | 11 | 0 | 51° – 60° |
| October | 59° | 33° | 1.6" | 5.1" | 8 | 3 | 41° – 50° |
| November | 46° | 22° | 1.5" | 20.2" | 8 | 16 | 26° – 41° |
| December | 36° | 14° | 1.5" | 16.5" | 7 | 28 | 20° – 31° |
| Year | 57° | 31° | 19.5" | 126.4" | 106 | 149 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Portland
Portland gets 20 inches of rain and melted snow a year. August is the wettest month and June the driest. Rain or snow falls on about 106 days a year. Snow covers the ground about 149 days of the year.
About 137 frost-free days a year
In half of years the last 32° night comes by May 17 and the first one by October 1. That leaves about 137 frost-free days for gardens, shorter than 91% of U.S. towns.
Heating and cooling a home in Portland
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Portland, 98% of that work is heating and 2% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Portland compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Portland averaged 2.3° warmer than the 1900s. The biggest change is in March (+3.7°). The shift is larger than in 99% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Portland’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 26° to 41°. August is the most reliable, staying within 6°.
Common questions about Portland’s climate
What is the coldest month in Portland?
January, with a typical high of 37° and a low of 13°.
What is the hottest month in Portland?
July, with a typical high of 80° and a low of 51°.
How much snow does Portland get?
About 126 inches in a normal winter, most of it in March.
When is the first frost in Portland?
In half of years the first 32° night comes by October 1, and the last spring frost by May 17.
What is the rainiest month in Portland?
August, with 2.2 inches of rain and melted snow. The year totals 20 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Portland itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Ouray, CO (5 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.