Opal weather by month
What a typical year looks like in Opal, Wyoming: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Kemmerer 2n, 18 km from Opal; records cover 1990–2026.
The year at a glance
- Precipitation a year
- 9.4 in239 mm
- Snow a year
- 50 in126 cm
- Last spring freeze
- Jun 19
- First fall freeze
- Aug 27
- Heating degree days
- 9,694
- Cooling degree days
- 50
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −18°−28° (heating, 99%) and 89°32° (cooling, 1%).
Month by month
Opal in January
Highs average 31°−1° and lows 2°−17°, with 0.69 in18 mm of precipitation and 12 in29 cm of snow in a typical January.
- Record high
- 48°9° (2018)
- Record low
- −30°−34° (2002)
- Heating degree days
- 1500
- Cooling degree days
- 0
Opal in February
Highs average 34°1° and lows 3°−16°, with 0.6 in15 mm of precipitation and 10 in24 cm of snow in a typical February.
- Record high
- 55°13° (2015)
- Record low
- −31°−35° (2011)
- Heating degree days
- 1303
- Cooling degree days
- 0
Opal in March
Highs average 43°6° and lows 13°−10°, with 0.65 in17 mm of precipitation and 6 in15 cm of snow in a typical March.
- Record high
- 69°21° (2015)
- Record low
- −25°−32° (1996)
- Heating degree days
- 1152
- Cooling degree days
- 0
Opal in April
Highs average 52°11° and lows 21°−6°, with 0.66 in17 mm of precipitation and 3 in8 cm of snow in a typical April.
- Record high
- 77°25° (2012)
- Record low
- −11°−24° (2023)
- Heating degree days
- 846
- Cooling degree days
- 0
Opal in May
Highs average 63°17° and lows 31°−1°, with 1.4 in35 mm of precipitation and 1.4 in3.6 cm of snow in a typical May.
- Record high
- 86°30° (2020)
- Record low
- 11°−12° (2013)
- Heating degree days
- 566
- Cooling degree days
- 0
Opal in June
Highs average 73°23° and lows 37°3°, with 0.94 in24 mm of precipitation and 0.1 in0.3 cm of snow in a typical June.
- Record high
- 93°34° (2013)
- Record low
- 19°−7° (2002)
- Heating degree days
- 303
- Cooling degree days
- 3
Opal in July
Highs average 83°28° and lows 43°6°, with 0.5 in13 mm of precipitation in a typical July.
- Record high
- 99°37° (1990)
- Record low
- 28°−2° (1993)
- Heating degree days
- 105
- Cooling degree days
- 32
Opal in August
Highs average 81°27° and lows 41°5°, with 0.86 in22 mm of precipitation in a typical August.
- Record high
- 96°36° (2025)
- Record low
- 21°−6° (1992)
- Heating degree days
- 142
- Cooling degree days
- 15
Opal in September
Highs average 72°22° and lows 32°0°, with 0.97 in25 mm of precipitation and 0.4 in1 cm of snow in a typical September.
- Record high
- 94°34° (2022)
- Record low
- 17°−8° (1995)
- Heating degree days
- 390
- Cooling degree days
- 0
Opal in OctoberThis month
Highs average 57°14° and lows 23°−5°, with 0.84 in21 mm of precipitation and 1.8 in4.6 cm of snow in a typical October.
- Record high
- 81°27° (2024)
- Record low
- −19°−28° (2019)
- Heating degree days
- 773
- Cooling degree days
- 0
Opal in November
Highs average 42°6° and lows 13°−11°, with 0.65 in17 mm of precipitation and 6 in16 cm of snow in a typical November.
- Record high
- 68°20° (2020)
- Record low
- −25°−32° (1993)
- Heating degree days
- 1128
- Cooling degree days
- 0
Opal in December
Highs average 31°0° and lows 3°−16°, with 0.67 in17 mm of precipitation and 10 in24 cm of snow in a typical December.
- Record high
- 64°18° (1998)
- Record low
- −39° (1990)
- Heating degree days
- 1486
- Cooling degree days
- 0