Prospect weather by month
What a typical year looks like in Prospect, Oregon: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Prospect 2 SW, 4 km from Prospect; records cover 1905–2026.
The year at a glance
- Precipitation a year
- 41.3 in1049 mm
- Snow a year
- 21 in53 cm
- Last spring freeze
- May 21
- First fall freeze
- Oct 2
- Heating degree days
- 4,887
- Cooling degree days
- 433
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 18°−8° (heating, 99%) and 100°38° (cooling, 1%).
Month by month
Prospect in January
Highs average 50°10° and lows 30°−1°, with 6 in152 mm of precipitation and 8 in19 cm of snow in a typical January.
- Record high
- 73°23° (2015)
- Record low
- −12°−24° (1937)
- Heating degree days
- 772
- Cooling degree days
- 0
Prospect in February
Highs average 54°12° and lows 31°−1°, with 4.4 in112 mm of precipitation and 3 in8 cm of snow in a typical February.
- Record high
- 76°24° (1977)
- Record low
- −2°−19° (1950)
- Heating degree days
- 638
- Cooling degree days
- 0
Prospect in March
Highs average 58°14° and lows 33°0°, with 4.4 in111 mm of precipitation and 2.3 in5.8 cm of snow in a typical March.
- Record high
- 88°31° (1911)
- Record low
- 5°−15° (1971)
- Heating degree days
- 612
- Cooling degree days
- 0
Prospect in April
Highs average 62°17° and lows 35°2°, with 3.7 in94 mm of precipitation and 1 in2.5 cm of snow in a typical April.
- Record high
- 95°35° (1926)
- Record low
- 17°−8° (1911)
- Heating degree days
- 489
- Cooling degree days
- 0
Prospect in May
Highs average 71°22° and lows 41°5°, with 2.6 in66 mm of precipitation in a typical May.
- Record high
- 102°39° (1983)
- Record low
- 20°−7° (2011)
- Heating degree days
- 294
- Cooling degree days
- 10
Prospect in June
Highs average 78°26° and lows 45°7°, with 1.3 in32 mm of precipitation in a typical June.
- Record high
- 109°43° (2021)
- Record low
- 27°−3° (1917)
- Heating degree days
- 144
- Cooling degree days
- 39
Prospect in July
Highs average 89°32° and lows 50°10°, with 0.57 in14 mm of precipitation in a typical July.
- Record high
- 107°42° (2022)
- Record low
- 30°−1° (1906)
- Heating degree days
- 23
- Cooling degree days
- 163
Prospect in August
Highs average 89°32° and lows 49°10°, with 0.47 in12 mm of precipitation in a typical August.
- Record high
- 110°43° (1981)
- Record low
- 27°−3° (1910)
- Heating degree days
- 22
- Cooling degree days
- 154
Prospect in September
Highs average 84°29° and lows 44°7°, with 1.2 in29 mm of precipitation in a typical September.
- Record high
- 106°41° (1955)
- Record low
- 20°−7° (1906)
- Heating degree days
- 104
- Cooling degree days
- 62
Prospect in OctoberThis month
Highs average 70°21° and lows 38°3°, with 3.3 in83 mm of precipitation in a typical October.
- Record high
- 98°37° (1980)
- Record low
- 12°−11° (1949)
- Heating degree days
- 348
- Cooling degree days
- 5
Prospect in November
Highs average 55°13° and lows 34°1°, with 6.3 in160 mm of precipitation and 2.9 in7.4 cm of snow in a typical November.
- Record high
- 82°28° (1949)
- Record low
- 2°−17° (1955)
- Heating degree days
- 627
- Cooling degree days
- 0
Prospect in December
Highs average 48°9° and lows 30°−1°, with 7.2 in183 mm of precipitation and 4 in10 cm of snow in a typical December.
- Record high
- 71°22° (1985)
- Record low
- −8°−22° (1972)
- Heating degree days
- 814
- Cooling degree days
- 0