Jefferson weather by month
What a typical year looks like in Jefferson, Oregon: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Salem Airport (mcnary Field), 21 km from Jefferson; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 40.1 in1018 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 15
- First fall freeze
- Oct 30
- Heating degree days
- 4,340
- Cooling degree days
- 401
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 22°−6° (heating, 99%) and 96°36° (cooling, 1%).
Month by month
Jefferson in January
Highs average 48°9° and lows 36°2°, with 6.1 in154 mm of precipitation in a typical January.
- Record high
- 68°20° (1896)
- Record low
- −10°−23° (1950)
- Heating degree days
- 710
- Cooling degree days
- 0
Jefferson in February
Highs average 52°11° and lows 36°2°, with 4.5 in115 mm of precipitation in a typical February.
- Record high
- 72°22° (1968)
- Record low
- −4°−20° (1899)
- Heating degree days
- 588
- Cooling degree days
- 0
Jefferson in March
Highs average 57°14° and lows 38°3°, with 4.4 in110 mm of precipitation in a typical March.
- Record high
- 80°27° (1923)
- Record low
- 12°−11° (1971)
- Heating degree days
- 541
- Cooling degree days
- 0
Jefferson in April
Highs average 62°16° and lows 41°5°, with 3.1 in79 mm of precipitation in a typical April.
- Record high
- 93°34° (1926)
- Record low
- 23°−5° (1968)
- Heating degree days
- 412
- Cooling degree days
- 1
Jefferson in May
Highs average 69°21° and lows 46°8°, with 2.3 in57 mm of precipitation in a typical May.
- Record high
- 100°38° (1983)
- Record low
- 25°−4° (1954)
- Heating degree days
- 239
- Cooling degree days
- 11
Jefferson in June
Highs average 75°24° and lows 51°10°, with 1.3 in32 mm of precipitation in a typical June.
- Record high
- 117°47° (2021)
- Record low
- 32°0° (1899)
- Heating degree days
- 108
- Cooling degree days
- 39
Jefferson in July
Highs average 84°29° and lows 55°13°, with 0.25 in6.4 mm of precipitation in a typical July.
- Record high
- 108°42° (1927)
- Record low
- 35°2° (1899)
- Heating degree days
- 15
- Cooling degree days
- 148
Jefferson in August
Highs average 84°29° and lows 55°13°, with 0.39 in9.9 mm of precipitation in a typical August.
- Record high
- 108°42° (1981)
- Record low
- 30°−1° (1920)
- Heating degree days
- 16
- Cooling degree days
- 146
Jefferson in September
Highs average 78°25° and lows 51°10°, with 1.5 in37 mm of precipitation in a typical September.
- Record high
- 104°40° (1988)
- Record low
- 26°−3° (1934)
- Heating degree days
- 82
- Cooling degree days
- 54
Jefferson in OctoberThis month
Highs average 65°18° and lows 44°7°, with 3.5 in88 mm of precipitation in a typical October.
- Record high
- 93°34° (1970)
- Record low
- 19°−7° (1919)
- Heating degree days
- 332
- Cooling degree days
- 2
Jefferson in November
Highs average 54°12° and lows 39°4°, with 6 in151 mm of precipitation in a typical November.
- Record high
- 74°23° (2010)
- Record low
- 9°−13° (1955)
- Heating degree days
- 561
- Cooling degree days
- 0
Jefferson in December
Highs average 47°9° and lows 35°2°, with 7 in177 mm of precipitation in a typical December.
- Record high
- 72°22° (1929)
- Record low
- −12°−24° (1972)
- Heating degree days
- 736
- Cooling degree days
- 0