Why weather by month
What a typical year looks like in Why, Arizona: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Ajo, 17 km from Why; records cover 1915–2026.
The year at a glance
- Precipitation a year
- 7 in177 mm
- Snow a year
- Rare
- Last spring freeze
- Feb 4
- First fall freeze
- Dec 9
- Heating degree days
- 1,040
- Cooling degree days
- 4,177
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 33°1° (heating, 99%) and 112°44° (cooling, 1%).
Month by month
Why in January
Highs average 68°20° and lows 45°7°, with 0.69 in18 mm of precipitation and 0.1 in0.3 cm of snow in a typical January.
- Record high
- 85°29° (1971)
- Record low
- 17°−8° (1937)
- Heating degree days
- 278
- Cooling degree days
- 5
Why in February
Highs average 71°21° and lows 48°9°, with 0.8 in20 mm of precipitation in a typical February.
- Record high
- 97°36° (2026)
- Record low
- 22°−6° (1923)
- Heating degree days
- 183
- Cooling degree days
- 20
Why in March
Highs average 77°25° and lows 52°11°, with 0.76 in19 mm of precipitation in a typical March.
- Record high
- 110°43° (2026)
- Record low
- 27°−3° (1971)
- Heating degree days
- 104
- Cooling degree days
- 87
Why in April
Highs average 84°29° and lows 57°14°, with 0.17 in4.3 mm of precipitation in a typical April.
- Record high
- 105°41° (2020)
- Record low
- 33°1° (2013)
- Heating degree days
- 31
- Cooling degree days
- 200
Why in May
Highs average 92°33° and lows 66°19°, with 0.1 in2.5 mm of precipitation in a typical May.
- Record high
- 112°44° (2026)
- Record low
- 31°−1° (1921)
- Heating degree days
- 4
- Cooling degree days
- 431
Why in June
Highs average 101°38° and lows 74°23°, with 0.08 in2 mm of precipitation in a typical June.
- Record high
- 119°48° (2016)
- Record low
- 44°7° (2017)
- Heating degree days
- 0
- Cooling degree days
- 676
Why in July
Highs average 104°40° and lows 80°27°, with 0.63 in16 mm of precipitation in a typical July.
- Record high
- 118°48° (2017)
- Record low
- 58°14° (1921)
- Heating degree days
- 0
- Cooling degree days
- 829
Why in August
Highs average 103°39° and lows 79°26°, with 1.4 in36 mm of precipitation in a typical August.
- Record high
- 120°49° (2025)
- Record low
- 57°14° (1916)
- Heating degree days
- 0
- Cooling degree days
- 809
Why in September
Highs average 99°37° and lows 74°24°, with 0.81 in21 mm of precipitation in a typical September.
- Record high
- 118°48° (2024)
- Record low
- 41°5° (2013)
- Heating degree days
- 0
- Cooling degree days
- 652
Why in OctoberThis month
Highs average 89°32° and lows 64°18°, with 0.44 in11 mm of precipitation in a typical October.
- Record high
- 113°45° (2024)
- Record low
- 32°0° (1971)
- Heating degree days
- 9
- Cooling degree days
- 371
Why in November
Highs average 77°25° and lows 51°11°, with 0.45 in11 mm of precipitation in a typical November.
- Record high
- 98°37° (2020)
- Record low
- 30°−1° (1919)
- Heating degree days
- 117
- Cooling degree days
- 93
Why in December
Highs average 67°19° and lows 43°6°, with 0.62 in16 mm of precipitation in a typical December.
- Record high
- 88°31° (1999)
- Record low
- 22°−6° (1954)
- Heating degree days
- 314
- Cooling degree days
- 4