Portland, OR weather in May
In May, Portland sees highs around 68°F and lows around 49°F: mild, with frequent rain. There are about 13 days with rain.
- Normal high
- 68°F
- Normal low
- 49°F
- Wet days
- 13
- 2.5 in total
- Muggy days
- 0
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 65°F | 70°F |
| Normal low | 47°F | 51°F |
| Chance of a wet day | 49% | 39% |
| Sunrise / sunset | 5:58 am / 8:17 pm | 5:25 am / 8:51 pm |
| Daylight | 14.3 h | 15.4 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Pacific Time).
A typical May day
- 6 am52°Fdew point 47°F
- 9 am57°Fdew point 47°F
- Noon63°Fdew point 47°F
- 3 pm67°Fdew point 46°F
- 6 pm65°Fdew point 46°F
- 9 pm59°Fdew point 47°F
NOAA hourly normals (local standard time) from Portland Intl Airport (6 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F14 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow13 of 31
- Notable rainat least 0.10 in7 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain in May
Normal precipitation is 2.5 in; a dry May brings about 1.6 in and a wet one about 3.4 in (25th and 75th percentiles). About 1 day brings half an inch or more.
How May varies from year to year
- Warmest May, 1991-20201992: average high 76°F
- Coolest May1991: average high 62°F
- Wettest May1998: 5.5 in
- Driest May1992: 0.1 in
- Highest reading99°F (May 22, 2001)
- Lowest reading37°F (May 10, 2012)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 61°F | 68°F | 73°F |
| Normal low | 44°F | 49°F | 53°F |
| Wet days | 17 | 13 | 9 |
| Comfortable days | 8 | 14 | 19 |
| Daylight | 13.5 h | 14.9 h | 15.6 h |
Highs change by +7°F from April and +5°F into June.
Nearby alternatives in May
- Drier: Bend, OR121 mi · high 66°F · 6 wet days
- Cooler: Cannon Beach, OR67 mi · high 61°F · 14 wet days
How Portland ranks in May
- Normal high304th warmest of 378 cities; 4th of 6 in Oregon
- Wet days337th driest of 378
- Comfortable days147th most of 339
What to pack for Portland in May
- A rain jacket or umbrella – rain on about 13 days
Heating and cooling
May has 217 heating degree days and 21 cooling degree days (base 65°F), 5% of the year's total heating and cooling demand.
Questions
How cold is Portland in May?
The normal high is 68°F and the normal low is 49°F. From 1991 to 2020 the coldest May reading was 37°F (most recently on May 10, 2012).
Does it rain a lot in Portland in May?
About 13 days in May have at least 0.01 in of precipitation, and the normal total is 2.5 in. The wettest May in 1991-2020 was in 1998 (5.6 in); the driest was in 1992 (0.1 in).
Is May a good time to visit Portland?
May ranks 5th of 12 months on our comfort score for Portland (71 out of 100). It has about 14 comfortable days and about 1 day at 90°F or hotter. The best month is June.
Where the numbers come from
- Temperature: Portland Kgw-Tv (USC00356749), 0.7 mi WSW of the city center, 159 ft (127 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Rain, snowfall, snow depth, frost dates and humidity and wind by hour: Portland Intl Airport (USW00024229), 5.9 mi NE of the city center, 19 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Portland International Airport (726980-24229), 6.0 mi NNE of the city center, 22 ft . Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).