March is one of the cooler months of the year in Sammamish, with average highs near 8.4°C and lows around 0.9°C (mean 4.7°C). It is a relatively wet time of year, averaging 175 mm of rainfall and 86% relative humidity across the period.
March is one of the cooler months of the year in Sammamish. Across 45 years of records, the warmest March in Sammamish was 1992 — when the month averaged 8.6°C — while the coldest was 2009 at 1.4°C. Typical March days reach 8.4°C with nights near 0.9°C. The long-term trend is cooling, about 0.2°C per decade.
March is a relatively wet time of year in Sammamish, averaging 175 mm of rainfall. The wettest March on record was 2014 with 352 mm, while the driest was 2019 at 40 mm.
Relative humidity in Sammamish during March averages 86%. The most humid March was 2025 at 93%, and the least humid was 1992 at 77%.
March receives about 2.9 kWh/m²/day of solar energy in Sammamish. The sunniest March was 2019 at 3.7 kWh/m²/day, and the cloudiest was 2017 at 2.3.
Average wind speed in Sammamish during March is 0.3 m/s. The windiest Marchs were 2022, 2023 and 2024, among others at 0.3 m/s, while the calmest were 2017 and 2025 at 0.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 4.9°C | 5.2°C | 4.2°C | 4.7°C | 4.3°C | -0.6°C |
| Avg High | 8.8°C | 9.2°C | 7.7°C | 8.3°C | 7.9°C | -0.9°C |
| Avg Low | 1.0°C | 1.1°C | 0.7°C | 1.1°C | 0.8°C | -0.2°C |
| Avg Rain | 177 mm | 151 mm | 182 mm | 205 mm | 148 mm | -28 mm |
March temperatures in Sammamish have fallen by about 0.5°C between 1981–1985 and 2021–2025.
March has ranged from a record low of -11.7°C (1989) to a record high of 22.8°C (1994).
Rainfall in March is a relatively wet time of year, averaging 175 mm, with a wettest year of 352 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.4°C per decade while lows fell 0.1°C per decade, narrowing the gap between day and night.
A good time to visit Sammamish
March is a good time to visit Sammamish, with days averaging 8.4°C and nights around 0.9°C (mean 4.7°C, cooler than Sammamish's yearly average) and higher rainfall. August and July are marginally more temperate, but March still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 7.0°C | 4.1°C | 1.2°C | 17.6°C | -3.0°C | 256 mm | 93% | 0.2 m/s | 2.6 |
| 2024 | 9.2°C | 5.3°C | 1.5°C | 19.7°C | -5.8°C | 116 mm | 86% | 0.3 m/s | 3.1 |
| 2023 | 6.9°C | 3.3°C | -0.4°C | 14.7°C | -3.9°C | 124 mm | 86% | 0.3 m/s | 3 |
| 2022 | 8.9°C | 5.6°C | 2.3°C | 17.7°C | -3.7°C | 143 mm | 88% | 0.3 m/s | 2.9 |
| 2021 | 8.1°C | 4.0°C | -0.1°C | 15.5°C | -2.9°C | 109 mm | 86% | 0.3 m/s | 3.3 |
| 2020 | 7.2°C | 3.7°C | 0.3°C | 14.1°C | -7.0°C | 142 mm | 85% | 0.3 m/s | 3.2 |
| 2019 | 8.7°C | 4.1°C | -0.5°C | 17.3°C | -9.1°C | 40 mm | 83% | 0.3 m/s | 3.7 |
| 2018 | 7.7°C | 4.0°C | 0.3°C | 14.0°C | -4.5°C | 114 mm | 87% | 0.3 m/s | 3.1 |
| 2017 | 6.6°C | 3.9°C | 1.2°C | 11.1°C | -2.0°C | 314 mm | 93% | 0.2 m/s | 2.3 |
| 2016 | 9.5°C | 5.9°C | 2.4°C | 18.8°C | -3.3°C | 222 mm | 86% | 0.3 m/s | 2.9 |
| 2015 | 11.8°C | 7.8°C | 3.9°C | 19.1°C | -1.8°C | 153 mm | 80% | 0.3 m/s | 3.1 |
| 2014 🌧️ | 8.3°C | 4.8°C | 1.3°C | 14.5°C | -4.1°C | 352 mm | 88% | 0.3 m/s | 2.8 |
| 2013 | 8.5°C | 4.8°C | 1.1°C | 20.7°C | -3.7°C | 163 mm | 87% | 0.3 m/s | 2.9 |
| 2012 | 5.7°C | 2.7°C | -0.3°C | 12.9°C | -3.6°C | 256 mm | 90% | 0.3 m/s | 2.6 |
| 2011 | 6.6°C | 3.4°C | 0.3°C | 12.1°C | -3.4°C | 297 mm | 91% | 0.3 m/s | 2.4 |
| 2010 | 9.3°C | 5.2°C | 1.1°C | 15.5°C | -4.3°C | 139 mm | 84% | 0.3 m/s | 3.1 |
| 2009 ❄️ | 4.8°C | 1.4°C | -2.0°C | 10.0°C | -10.5°C | 214 mm | 90% | 0.3 m/s | 2.8 |
| 2008 | 5.8°C | 2.6°C | -0.6°C | 12.3°C | -3.4°C | 158 mm | 89% | 0.3 m/s | 2.7 |
| 2007 | 8.9°C | 5.3°C | 1.7°C | 15.1°C | -7.6°C | 245 mm | 90% | 0.3 m/s | 2.6 |
| 2006 | 8.0°C | 3.9°C | -0.1°C | 13.4°C | -6.3°C | 95 mm | 84% | 0.3 m/s | 2.9 |
| 2005 | 10.6°C | 6.6°C | 2.5°C | 19.1°C | -2.0°C | 167 mm | 84% | 0.3 m/s | 3.1 |
| 2004 | 9.6°C | 5.9°C | 2.1°C | 18.9°C | -1.8°C | 139 mm | 86% | 0.3 m/s | 3 |
| 2003 | 8.0°C | 5.0°C | 2.0°C | 16.1°C | -3.3°C | 284 mm | 91% | 0.3 m/s | 2.6 |
| 2002 | 4.9°C | 2.1°C | -0.7°C | 11.6°C | -5.9°C | 210 mm | 90% | 0.3 m/s | 2.6 |
| 2001 | 8.7°C | 4.9°C | 1.1°C | 18.2°C | -2.0°C | 171 mm | 87% | 0.3 m/s | 2.9 |
| 2000 | 7.4°C | 4.0°C | 0.6°C | 13.7°C | -2.7°C | 141 mm | 89% | 0.3 m/s | 3 |
| 1999 | 7.1°C | 3.6°C | 0.1°C | 18.6°C | -4.6°C | 131 mm | 87% | 0.3 m/s | 2.8 |
| 1998 | 8.5°C | 5.1°C | 1.7°C | 15.3°C | -2.6°C | 150 mm | 87% | 0.3 m/s | 3 |
| 1997 | 6.7°C | 3.6°C | 0.5°C | 15.2°C | -4.1°C | 328 mm | 90% | 0.3 m/s | 2.6 |
| 1996 | 8.8°C | 4.6°C | 0.4°C | 16.9°C | -6.6°C | 116 mm | 83% | 0.3 m/s | 3.1 |
| 1995 | 9.4°C | 5.1°C | 0.8°C | 19.0°C | -6.1°C | 156 mm | 82% | 0.3 m/s | 3 |
| 1994 | 10.8°C | 6.4°C | 1.9°C | 22.8°C | -6.0°C | 134 mm | 82% | 0.3 m/s | 3.1 |
| 1993 | 9.7°C | 5.5°C | 1.3°C | 13.9°C | -2.5°C | 166 mm | 84% | 0.3 m/s | 2.9 |
| 1992 🔥 | 13.9°C | 8.6°C | 3.3°C | 19.1°C | -1.1°C | 43 mm | 77% | 0.3 m/s | 3.5 |
| 1991 | 7.4°C | 3.6°C | -0.1°C | 18.4°C | -3.7°C | 161 mm | 86% | 0.3 m/s | 3.1 |
| 1990 | 10.0°C | 5.7°C | 1.4°C | 16.2°C | -4.0°C | 127 mm | 83% | 0.3 m/s | 3.1 |
| 1989 | 6.4°C | 3.0°C | -0.4°C | 10.9°C | -11.7°C | 217 mm | 91% | 0.3 m/s | 2.5 |
| 1988 | 8.0°C | 4.2°C | 0.5°C | 17.3°C | -3.2°C | 254 mm | 86% | 0.3 m/s | 2.9 |
| 1987 | 9.7°C | 5.7°C | 1.8°C | 22.5°C | -2.6°C | 197 mm | 85% | 0.3 m/s | 3.1 |
| 1986 | 10.8°C | 6.5°C | 2.2°C | 17.5°C | -0.7°C | 133 mm | 85% | 0.3 m/s | 2.8 |
| 1985 | 7.4°C | 3.5°C | -0.5°C | 15.4°C | -3.9°C | 136 mm | 83% | 0.3 m/s | 3.3 |
| 1984 | 9.4°C | 5.7°C | 2.0°C | 16.8°C | -1.3°C | 184 mm | 88% | 0.3 m/s | 3.1 |
| 1983 | 10.0°C | 6.1°C | 2.2°C | 14.5°C | 0.2°C | 203 mm | 87% | 0.3 m/s | — |
| 1982 | 7.3°C | 3.5°C | -0.2°C | 14.0°C | -2.8°C | 158 mm | 85% | 0.3 m/s | — |
| 1981 | 10.3°C | 6.0°C | 1.6°C | 16.5°C | -3.2°C | 108 mm | 82% | 0.3 m/s | — |
Actual recorded March data for each year, 1981–2025 — sourced from NASA POWER.
The average high in March is around 8.4°C with lows near 0.9°C (mean 4.7°C), based on 45 years of NASA POWER data.
March averages 175 mm of rainfall in Sammamish, a relatively wet time of year. The wettest on record was 352 mm in 2014.
The hottest March reached 22.8°C in 1994. The coldest dipped to -11.7°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average March temperatures have fallen by about 0.5°C. Daytime highs moved from 8.9°C to 8°C and overnight lows from 1°C to 0.9°C over the same span.
March is one of the cooler months of the year in Sammamish and a relatively wet time of year, so plan for around 8.4°C daytime highs and 0.9°C at night.
Not quite — March is the 5th coolest month in Sammamish, averaging 4.7°C.
For March in Sammamish, pack warm layers and a jacket for chilly mornings, with typical highs of 8.4°C and lows of 0.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in March averages 86% — quite humid.
Average wind speed in March is 0.3 m/s. The windiest March on record averaged 0.3 m/s (1981).
The wettest March on record was 2014 with 352 mm. On average, March sees 175 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 Sammamish 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.
