Zillah weather by month
What a typical year looks like in Zillah, Washington: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Sunnyside No. 2, 20 km from Zillah; records cover 2013–2026.
The year at a glance
- Precipitation a year
- 8.3 in212 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 28
- First fall freeze
- Oct 9
- Heating degree days
- 5,832
- Cooling degree days
- 462
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 9°−13° (heating, 99%) and 99°37° (cooling, 1%).
Month by month
Zillah in January
Highs average 38°3° and lows 24°−4°, with 1 in26 mm of precipitation in a typical January.
- Record high
- 60°16° (2021)
- Record low
- −1°−18° (2017)
- Heating degree days
- 1060
- Cooling degree days
- 0
Zillah in February
Highs average 46°8° and lows 26°−3°, with 0.72 in18 mm of precipitation in a typical February.
- Record high
- 67°19° (2018)
- Record low
- −2°−19° (2014)
- Heating degree days
- 819
- Cooling degree days
- 0
Zillah in March
Highs average 56°13° and lows 30°−1°, with 0.71 in18 mm of precipitation in a typical March.
- Record high
- 80°27° (2025)
- Record low
- 6°−14° (2019)
- Heating degree days
- 682
- Cooling degree days
- 0
Zillah in April
Highs average 64°18° and lows 35°2°, with 0.64 in16 mm of precipitation in a typical April.
- Record high
- 88°31° (2023)
- Record low
- 17°−8° (2020)
- Heating degree days
- 460
- Cooling degree days
- 0
Zillah in May
Highs average 73°23° and lows 43°6°, with 0.82 in21 mm of precipitation in a typical May.
- Record high
- 93°34° (2020)
- Record low
- 27°−3° (2020)
- Heating degree days
- 234
- Cooling degree days
- 5
Zillah in June
Highs average 80°26° and lows 48°9°, with 0.66 in17 mm of precipitation in a typical June.
- Record high
- 109°43° (2021)
- Record low
- 35°2° (2016)
- Heating degree days
- 102
- Cooling degree days
- 69
Zillah in July
Highs average 88°31° and lows 54°12°, with 0.21 in5.3 mm of precipitation in a typical July.
- Record high
- 105°41° (2014)
- Record low
- 43°6° (2018)
- Heating degree days
- 11
- Cooling degree days
- 196
Zillah in August
Highs average 87°30° and lows 52°11°, with 0.25 in6.4 mm of precipitation in a typical August.
- Record high
- 104°40° (2024)
- Record low
- 42°6° (2024)
- Heating degree days
- 13
- Cooling degree days
- 155
Zillah in September
Highs average 79°26° and lows 45°7°, with 0.27 in6.9 mm of precipitation in a typical September.
- Record high
- 97°36° (2024)
- Record low
- 34°1° (2015)
- Heating degree days
- 136
- Cooling degree days
- 37
Zillah in OctoberThis month
Highs average 64°18° and lows 36°2°, with 0.86 in22 mm of precipitation in a typical October.
- Record high
- 85°29° (2014)
- Record low
- 13°−11° (2019)
- Heating degree days
- 460
- Cooling degree days
- 0
Zillah in November
Highs average 49°9° and lows 28°−2°, with 0.92 in23 mm of precipitation in a typical November.
- Record high
- 72°22° (2020)
- Record low
- 10°−12° (2014)
- Heating degree days
- 795
- Cooling degree days
- 0
Zillah in December
Highs average 38°3° and lows 24°−4°, with 1.3 in32 mm of precipitation in a typical December.
- Record high
- 70°21° (2021)
- Record low
- −5°−21° (2016)
- Heating degree days
- 1060
- Cooling degree days
- 0