Prosser weather by month
What a typical year looks like in Prosser, Washington: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Prosser, 1 km from Prosser; records cover 1925–2026.
The year at a glance
- Precipitation a year
- 8.7 in222 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 10
- First fall freeze
- Oct 23
- Heating degree days
- 5,172
- Cooling degree days
- 838
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 11°−12° (heating, 99%) and 101°38° (cooling, 1%).
Month by month
Prosser in January
Highs average 40°5° and lows 27°−3°, with 1.2 in31 mm of precipitation in a typical January.
- Record high
- 69°21° (1971)
- Record low
- −20°−29° (1930)
- Heating degree days
- 978
- Cooling degree days
- 0
Prosser in February
Highs average 47°8° and lows 29°−2°, with 0.9 in23 mm of precipitation in a typical February.
- Record high
- 69°21° (1932)
- Record low
- −20°−29° (1950)
- Heating degree days
- 766
- Cooling degree days
- 0
Prosser in March
Highs average 56°13° and lows 35°2°, with 0.69 in18 mm of precipitation in a typical March.
- Record high
- 81°27° (1960)
- Record low
- 6°−14° (1955)
- Heating degree days
- 608
- Cooling degree days
- 0
Prosser in April
Highs average 65°18° and lows 40°4°, with 0.74 in19 mm of precipitation in a typical April.
- Record high
- 91°33° (1977)
- Record low
- 14°−10° (1935)
- Heating degree days
- 384
- Cooling degree days
- 2
Prosser in May
Highs average 74°23° and lows 48°9°, with 0.88 in22 mm of precipitation in a typical May.
- Record high
- 100°38° (1983)
- Record low
- 26°−3° (1928)
- Heating degree days
- 168
- Cooling degree days
- 44
Prosser in June
Highs average 81°27° and lows 54°12°, with 0.68 in17 mm of precipitation in a typical June.
- Record high
- 114°46° (2021)
- Record low
- 30°−1° (2011)
- Heating degree days
- 55
- Cooling degree days
- 122
Prosser in July
Highs average 90°32° and lows 60°15°, with 0.21 in5.3 mm of precipitation in a typical July.
- Record high
- 111°44° (2002)
- Record low
- 31°−1° (2012)
- Heating degree days
- 7
- Cooling degree days
- 316
Prosser in August
Highs average 89°32° and lows 58°14°, with 0.16 in4.1 mm of precipitation in a typical August.
- Record high
- 106°41° (1998)
- Record low
- 36°2° (2000)
- Heating degree days
- 9
- Cooling degree days
- 270
Prosser in September
Highs average 80°27° and lows 50°10°, with 0.27 in6.9 mm of precipitation in a typical September.
- Record high
- 101°38° (2022)
- Record low
- 21°−6° (1926)
- Heating degree days
- 83
- Cooling degree days
- 80
Prosser in OctoberThis month
Highs average 65°18° and lows 41°5°, with 0.77 in20 mm of precipitation in a typical October.
- Record high
- 90°32° (1932)
- Record low
- 11°−12° (1935)
- Heating degree days
- 384
- Cooling degree days
- 4
Prosser in November
Highs average 49°10° and lows 32°0°, with 0.86 in22 mm of precipitation in a typical November.
- Record high
- 76°24° (1931)
- Record low
- −7°−22° (1985)
- Heating degree days
- 735
- Cooling degree days
- 0
Prosser in December
Highs average 40°4° and lows 26°−3°, with 1.3 in34 mm of precipitation in a typical December.
- Record high
- 70°21° (2021)
- Record low
- −11°−24° (1968)
- Heating degree days
- 995
- Cooling degree days
- 0