St. Helens weather by month
What a typical year looks like in St. Helens, Oregon: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Vancouver 4 Nne, 24 km from St. Helens; records cover 1891–2026.
The year at a glance
- Precipitation a year
- 42.3 in1074 mm
- Snow a year
- 0.8 in2 cm
- Last spring freeze
- Apr 16
- First fall freeze
- Oct 17
- Heating degree days
- 5,294
- Cooling degree days
- 191
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 19°−7° (heating, 99%) and 94°34° (cooling, 1%).
Month by month
St. Helens in January
Highs average 45°7° and lows 32°0°, with 6.1 in154 mm of precipitation and 0.5 in1.3 cm of snow in a typical January.
- Record high
- 65°18° (1931)
- Record low
- −8°−22° (1909)
- Heating degree days
- 818
- Cooling degree days
- 0
St. Helens in February
Highs average 49°10° and lows 32°0°, with 4.1 in105 mm of precipitation and 0.1 in0.3 cm of snow in a typical February.
- Record high
- 73°23° (1968)
- Record low
- −3°−19° (1950)
- Heating degree days
- 685
- Cooling degree days
- 0
St. Helens in March
Highs average 54°12° and lows 35°2°, with 4.4 in113 mm of precipitation in a typical March.
- Record high
- 83°28° (1930)
- Record low
- 18°−8° (1906)
- Heating degree days
- 637
- Cooling degree days
- 0
St. Helens in April
Highs average 59°15° and lows 38°4°, with 3.6 in91 mm of precipitation in a typical April.
- Record high
- 90°32° (1906)
- Record low
- 23°−5° (2008)
- Heating degree days
- 489
- Cooling degree days
- 0
St. Helens in May
Highs average 66°19° and lows 44°7°, with 2.8 in71 mm of precipitation in a typical May.
- Record high
- 99°37° (1983)
- Record low
- 28°−2° (1985)
- Heating degree days
- 309
- Cooling degree days
- 5
St. Helens in June
Highs average 71°22° and lows 49°9°, with 1.8 in47 mm of precipitation in a typical June.
- Record high
- 112°44° (2021)
- Record low
- 34°1° (1979)
- Heating degree days
- 175
- Cooling degree days
- 20
St. Helens in July
Highs average 78°26° and lows 53°12°, with 0.48 in12 mm of precipitation in a typical July.
- Record high
- 106°41° (2009)
- Record low
- 37°3° (1981)
- Heating degree days
- 60
- Cooling degree days
- 72
St. Helens in August
Highs average 79°26° and lows 52°11°, with 0.62 in16 mm of precipitation in a typical August.
- Record high
- 104°40° (2023)
- Record low
- 35°2° (1973)
- Heating degree days
- 57
- Cooling degree days
- 74
St. Helens in September
Highs average 74°23° and lows 47°8°, with 1.6 in41 mm of precipitation in a typical September.
- Record high
- 103°39° (1988)
- Record low
- 28°−2° (1970)
- Heating degree days
- 161
- Cooling degree days
- 20
St. Helens in OctoberThis month
Highs average 62°17° and lows 41°5°, with 3.6 in92 mm of precipitation in a typical October.
- Record high
- 90°32° (1987)
- Record low
- 19°−7° (2002)
- Heating degree days
- 425
- Cooling degree days
- 0
St. Helens in November
Highs average 51°11° and lows 36°2°, with 6.3 in160 mm of precipitation in a typical November.
- Record high
- 72°22° (1905)
- Record low
- 6°−14° (1896)
- Heating degree days
- 646
- Cooling degree days
- 0
St. Helens in December
Highs average 45°7° and lows 32°0°, with 6.8 in172 mm of precipitation and 0.2 in0.5 cm of snow in a typical December.
- Record high
- 65°18° (1950)
- Record low
- −10°−23° (1919)
- Heating degree days
- 832
- Cooling degree days
- 0