March is one of the cooler months of the year in Portland, with average highs near 3.6°C and lows around -0.9°C (mean 1.4°C). It is about average for rainfall, averaging 114 mm of rainfall and 82% relative humidity across the period.
March is one of the cooler months of the year in Portland. Across 45 years of records, the warmest March in Portland was 2012 — when the month averaged 4.5°C — while the coldest was 1984 at -2.1°C. Typical March days reach 3.6°C with nights near -0.9°C. The long-term trend is warming, about 0.4°C per decade.
March is about average for rainfall in Portland, averaging 114 mm of rainfall. The wettest March on record was 2024 with 301 mm, while the driest was 2006 at 26 mm.
Relative humidity in Portland during March averages 82%. The most humid Marchs were 1987 and 1993 at 87%, and the least humid was 2014 at 78%.
March receives about 3.7 kWh/m²/day of solar energy in Portland. The sunniest Marchs were 1985, 2006 and 2021 at 4.2 kWh/m²/day, and the cloudiest was 2001 at 3.2.
Average wind speed in Portland during March is 4.6 m/s. The windiest March was 2018 at 5.4 m/s, while the calmest was 1995 at 3.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 0.8°C | 0.8°C | 1.2°C | 1.5°C | 2.9°C | +2.1°C |
| Avg High | 3.2°C | 3.1°C | 3.4°C | 3.7°C | 5.0°C | +1.8°C |
| Avg Low | -1.7°C | -1.4°C | -1.0°C | -0.7°C | 0.7°C | +2.4°C |
| Avg Rain | 109 mm | 115 mm | 109 mm | 116 mm | 122 mm | +13 mm |
March temperatures in Portland have risen by about 2°C between 1981–1985 and 2021–2025.
March has ranged from a record low of -15.4°C (1989) to a record high of 16.2°C (2012).
Rainfall in March is about average for rainfall, averaging 114 mm, with a wettest year of 301 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
A quieter season to visit Portland
If your dates are flexible, the more temperate months of August and July tend to be the most comfortable for visiting Portland. That said, March — with days averaging 3.6°C and nights around -0.9°C (mean 1.4°C) and higher rainfall (114 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 4.7°C | 2.6°C | 0.5°C | 8.0°C | -9.2°C | 109 mm | 82% | 4.6 m/s | 3.5 |
| 2024 🌧️ | 4.9°C | 3.2°C | 1.6°C | 7.6°C | -6.2°C | 301 mm | 85% | 4.9 m/s | 3.5 |
| 2023 | 4.9°C | 3.0°C | 1.1°C | 7.3°C | -1.3°C | 72 mm | 81% | 4.8 m/s | 3.7 |
| 2022 | 5.1°C | 2.7°C | 0.2°C | 8.8°C | -8.6°C | 123 mm | 82% | 4.4 m/s | 3.8 |
| 2021 | 4.8°C | 2.3°C | -0.3°C | 12.3°C | -11.0°C | 53 mm | 80% | 4.9 m/s | 4.2 |
| 2020 | 5.8°C | 3.5°C | 1.1°C | 11.5°C | -5.0°C | 73 mm | 79% | 4.6 m/s | 3.9 |
| 2019 | 3.0°C | 1.0°C | -1.0°C | 8.8°C | -8.2°C | 88 mm | 78% | 4.5 m/s | 4 |
| 2018 | 3.4°C | 1.7°C | 0.0°C | 9.4°C | -7.3°C | 106 mm | 82% | 5.4 m/s | 3.5 |
| 2017 | 2.1°C | -0.3°C | -2.7°C | 9.2°C | -11.5°C | 139 mm | 80% | 5.2 m/s | 3.7 |
| 2016 | 4.9°C | 2.7°C | 0.5°C | 11.3°C | -7.3°C | 121 mm | 81% | 4.4 m/s | 3.6 |
| 2015 | 1.8°C | -0.9°C | -3.5°C | 5.9°C | -11.6°C | 56 mm | 81% | 4.9 m/s | 3.8 |
| 2014 | 1.4°C | -1.1°C | -3.6°C | 6.2°C | -9.3°C | 119 mm | 78% | 4.8 m/s | 3.5 |
| 2013 | 4.0°C | 2.0°C | 0.1°C | 8.6°C | -5.6°C | 59 mm | 81% | 4.9 m/s | 3.6 |
| 2012 🔥 | 6.9°C | 4.5°C | 2.1°C | 16.2°C | -6.2°C | 55 mm | 82% | 3.9 m/s | 3.9 |
| 2011 | 3.8°C | 1.7°C | -0.5°C | 10.7°C | -10.3°C | 130 mm | 81% | 4.8 m/s | 3.6 |
| 2010 | 5.7°C | 3.8°C | 2.0°C | 11.4°C | -3.4°C | 286 mm | 84% | 4.6 m/s | 3.5 |
| 2009 | 3.2°C | 1.2°C | -0.9°C | 7.8°C | -8.3°C | 79 mm | 81% | 4.1 m/s | 3.7 |
| 2008 | 3.1°C | 1.0°C | -1.2°C | 7.9°C | -4.8°C | 151 mm | 81% | 4.9 m/s | 3.4 |
| 2007 | 3.4°C | 0.8°C | -1.9°C | 8.0°C | -14.5°C | 123 mm | 83% | 5 m/s | 3.7 |
| 2006 | 4.0°C | 1.8°C | -0.5°C | 10.8°C | -7.2°C | 26 mm | 80% | 4.2 m/s | 4.2 |
| 2005 | 2.1°C | -0.2°C | -2.5°C | 7.7°C | -11.6°C | 124 mm | 83% | 4.4 m/s | 3.9 |
| 2004 | 3.2°C | 1.3°C | -0.6°C | 8.5°C | -6.2°C | 54 mm | 81% | 4 m/s | 3.5 |
| 2003 | 3.2°C | 0.4°C | -2.4°C | 8.2°C | -15.0°C | 109 mm | 85% | 4.3 m/s | 3.4 |
| 2002 | 4.3°C | 2.2°C | 0.1°C | 10.5°C | -7.2°C | 115 mm | 79% | 4.2 m/s | 3.5 |
| 2001 | 2.0°C | 0.4°C | -1.2°C | 6.2°C | -8.5°C | 194 mm | 82% | 4.7 m/s | 3.2 |
| 2000 | 5.5°C | 3.2°C | 0.9°C | 10.2°C | -6.3°C | 110 mm | 83% | 4.3 m/s | 3.7 |
| 1999 | 4.1°C | 1.8°C | -0.5°C | 9.7°C | -9.6°C | 147 mm | 84% | 4.9 m/s | 3.7 |
| 1998 | 4.1°C | 1.9°C | -0.3°C | 14.4°C | -11.0°C | 116 mm | 87% | 4.1 m/s | 3.5 |
| 1997 | 2.4°C | 0.1°C | -2.2°C | 9.1°C | -9.4°C | 121 mm | 82% | 4.9 m/s | 3.5 |
| 1996 | 2.0°C | -0.1°C | -2.3°C | 6.9°C | -8.7°C | 73 mm | 81% | 4.3 m/s | 3.8 |
| 1995 | 3.2°C | 1.2°C | -0.7°C | 8.3°C | -7.4°C | 60 mm | 85% | 3.7 m/s | 3.4 |
| 1994 | 2.8°C | 0.7°C | -1.4°C | 7.0°C | -8.7°C | 167 mm | 86% | 4.3 m/s | 3.5 |
| 1993 | 2.2°C | -0.5°C | -3.1°C | 8.3°C | -12.5°C | 158 mm | 87% | 4.6 m/s | 3.5 |
| 1992 | 2.0°C | -0.3°C | -2.7°C | 7.4°C | -13.8°C | 104 mm | 80% | 4.6 m/s | 3.7 |
| 1991 | 4.1°C | 2.1°C | 0.0°C | 11.6°C | -6.5°C | 159 mm | 83% | 4.8 m/s | 3.4 |
| 1990 | 3.8°C | 1.3°C | -1.3°C | 9.5°C | -8.8°C | 46 mm | 81% | 4.1 m/s | 3.8 |
| 1989 | 2.2°C | -0.2°C | -2.6°C | 10.2°C | -15.4°C | 74 mm | 81% | 4.5 m/s | 3.8 |
| 1988 | 3.4°C | 0.6°C | -2.1°C | 9.4°C | -10.7°C | 53 mm | 79% | 4.7 m/s | 3.9 |
| 1987 | 3.3°C | 1.2°C | -0.9°C | 10.6°C | -11.3°C | 123 mm | 87% | 4.3 m/s | 3.3 |
| 1986 | 4.0°C | 1.3°C | -1.4°C | 9.6°C | -12.1°C | 111 mm | 83% | 4.3 m/s | 3.9 |
| 1985 | 4.1°C | 1.4°C | -1.4°C | 11.3°C | -8.5°C | 90 mm | 78% | 4.8 m/s | 4.2 |
| 1984 ❄️ | 0.2°C | -2.1°C | -4.3°C | 5.1°C | -12.5°C | 148 mm | 86% | 5.2 m/s | 3.5 |
| 1983 | 4.3°C | 2.2°C | 0.1°C | 8.0°C | -6.0°C | 258 mm | 83% | 5.1 m/s | — |
| 1982 | 3.3°C | 0.8°C | -1.7°C | 7.5°C | -11.5°C | 90 mm | 84% | 4.4 m/s | — |
| 1981 | 4.1°C | 1.8°C | -0.6°C | 11.9°C | -6.2°C | 36 mm | 79% | 4.3 m/s | — |
Actual recorded March data for each year, 1981–2025 — sourced from NASA POWER.
The average high in March is around 3.6°C with lows near -0.9°C (mean 1.4°C), based on 45 years of NASA POWER data.
March averages 114 mm of rainfall in Portland, about average for rainfall. The wettest on record was 301 mm in 2024.
The hottest March reached 16.2°C in 2012. The coldest dipped to -15.4°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average March temperatures have risen by about 2°C. Daytime highs moved from 3.2°C to 4.9°C and overnight lows from -1.6°C to 0.6°C over the same span.
March is one of the cooler months of the year in Portland and about average for rainfall, so plan for around 3.6°C daytime highs and -0.9°C at night.
Not quite — March is the 3rd coolest month in Portland, averaging 1.4°C.
For March in Portland, pack warm layers and a jacket for chilly mornings, with typical highs of 3.6°C and lows of -0.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in March averages 82% — quite humid.
Average wind speed in March is 4.6 m/s. The windiest March on record averaged 5.4 m/s (2018).
The wettest March on record was 2024 with 301 mm. On average, March sees 114 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Portland behaves each March, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for March specifically, along with year-by-year records and how the month has changed over the decades.
