Phoenix, Arizona weather in January

Averages from 2021–2025 (155 days of record).

Average high

64°F

Average low

41°F

Rainy days

~4 per month

Total precipitation

1.3 in

Warmest recorded

77°F

Coldest recorded

30°F

Expect January days in Phoenix, Arizona to top out around 64°F and cool to about 41°F overnight, with roughly 4 days of measurable rain across the month. In recent years January has ranged from 30°F to 77°F.