Riverton weather by month
What a typical year looks like in Riverton, Wyoming: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at RIVERTON, 1 km from Riverton; records cover 1907–2026.
The year at a glance
- Precipitation a year
- 9.5 in241 mm
- Snow a year
- 44 in113 cm
- Last spring freeze
- May 13
- First fall freeze
- Sep 21
- Heating degree days
- 8,101
- Cooling degree days
- 468
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −17°−27° (heating, 99%) and 97°36° (cooling, 1%).
Month by month
Riverton in January
Highs average 29°−2° and lows 4°−15°, with 0.35 in8.9 mm of precipitation and 6 in14 cm of snow in a typical January.
- Record high
- 63°17° (1953)
- Record low
- −46°−43° (1930)
- Heating degree days
- 1505
- Cooling degree days
- 0
Riverton in February
Highs average 36°2° and lows 10°−12°, with 0.43 in11 mm of precipitation and 7 in19 cm of snow in a typical February.
- Record high
- 71°22° (1951)
- Record low
- −45°−43° (1936)
- Heating degree days
- 1188
- Cooling degree days
- 0
Riverton in March
Highs average 49°10° and lows 22°−5°, with 0.71 in18 mm of precipitation and 7 in17 cm of snow in a typical March.
- Record high
- 84°29° (2026)
- Record low
- −24°−31° (1920)
- Heating degree days
- 908
- Cooling degree days
- 0
Riverton in April
Highs average 58°14° and lows 31°−1°, with 1.3 in33 mm of precipitation and 7 in18 cm of snow in a typical April.
- Record high
- 87°31° (1987)
- Record low
- −18°−28° (1936)
- Heating degree days
- 623
- Cooling degree days
- 0
Riverton in May
Highs average 67°20° and lows 40°5°, with 2 in50 mm of precipitation and 2.1 in5.3 cm of snow in a typical May.
- Record high
- 96°36° (1984)
- Record low
- 15°−9° (1909)
- Heating degree days
- 355
- Cooling degree days
- 9
Riverton in June
Highs average 79°26° and lows 49°9°, with 1.1 in28 mm of precipitation in a typical June.
- Record high
- 102°39° (1970)
- Record low
- 26°−3° (1951)
- Heating degree days
- 108
- Cooling degree days
- 69
Riverton in July
Highs average 88°31° and lows 55°13°, with 0.7 in18 mm of precipitation in a typical July.
- Record high
- 106°41° (2026)
- Record low
- 30°−1° (1986)
- Heating degree days
- 16
- Cooling degree days
- 212
Riverton in August
Highs average 86°30° and lows 52°11°, with 0.45 in11 mm of precipitation in a typical August.
- Record high
- 103°39° (1988)
- Record low
- 29°−2° (1908)
- Heating degree days
- 30
- Cooling degree days
- 153
Riverton in September
Highs average 74°24° and lows 43°6°, with 0.8 in20 mm of precipitation and 0.6 in1.5 cm of snow in a typical September.
- Record high
- 98°37° (1990)
- Record low
- 9°−13° (1926)
- Heating degree days
- 220
- Cooling degree days
- 24
Riverton in OctoberThis month
Highs average 59°15° and lows 30°−1°, with 0.93 in24 mm of precipitation and 4 in11 cm of snow in a typical October.
- Record high
- 90°32° (1980)
- Record low
- −13°−25° (2019)
- Heating degree days
- 627
- Cooling degree days
- 1
Riverton in November
Highs average 43°6° and lows 17°−8°, with 0.44 in11 mm of precipitation and 5 in13 cm of snow in a typical November.
- Record high
- 73°23° (1931)
- Record low
- −28°−33° (1985)
- Heating degree days
- 1053
- Cooling degree days
- 0
Riverton in December
Highs average 30°−1° and lows 6°−15°, with 0.31 in7.9 mm of precipitation and 5 in13 cm of snow in a typical December.
- Record high
- 65°18° (1933)
- Record low
- −46°−43° (1978)
- Heating degree days
- 1468
- Cooling degree days
- 0