Sinclair weather by month
What a typical year looks like in Sinclair, Wyoming: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Rawlins Airport, 7 km from Sinclair; records cover 1951–2026.
The year at a glance
- Precipitation a year
- 9 in230 mm
- Snow a year
- Rare
- Last spring freeze
- Jun 3
- First fall freeze
- Sep 17
- Heating degree days
- 8,166
- Cooling degree days
- 225
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −10°−23° (heating, 99%) and 93°34° (cooling, 1%).
Month by month
Sinclair in January
Highs average 32°0° and lows 13°−10°, with 0.42 in11 mm of precipitation in a typical January.
- Record high
- 56°13° (1953)
- Record low
- −36°−38° (1963)
- Heating degree days
- 1322
- Cooling degree days
- 0
Sinclair in February
Highs average 34°1° and lows 15°−10°, with 0.48 in12 mm of precipitation in a typical February.
- Record high
- 58°14° (1962)
- Record low
- −36°−38° (1989)
- Heating degree days
- 1142
- Cooling degree days
- 0
Sinclair in March
Highs average 45°7° and lows 22°−6°, with 0.66 in17 mm of precipitation in a typical March.
- Record high
- 78°26° (2026)
- Record low
- −24°−31° (2022)
- Heating degree days
- 975
- Cooling degree days
- 0
Sinclair in April
Highs average 54°12° and lows 27°−3°, with 1.3 in32 mm of precipitation in a typical April.
- Record high
- 79°26° (2012)
- Record low
- −11°−24° (1970)
- Heating degree days
- 738
- Cooling degree days
- 0
Sinclair in May
Highs average 64°18° and lows 36°2°, with 1.5 in37 mm of precipitation in a typical May.
- Record high
- 88°31° (2002)
- Record low
- 8°−13° (2026)
- Heating degree days
- 470
- Cooling degree days
- 1
Sinclair in June
Highs average 77°25° and lows 43°6°, with 0.87 in22 mm of precipitation in a typical June.
- Record high
- 97°36° (1954)
- Record low
- 21°−6° (1951)
- Heating degree days
- 174
- Cooling degree days
- 21
Sinclair in July
Highs average 85°30° and lows 51°10°, with 0.72 in18 mm of precipitation in a typical July.
- Record high
- 98°37° (1954)
- Record low
- 32°0° (1993)
- Heating degree days
- 26
- Cooling degree days
- 118
Sinclair in August
Highs average 83°28° and lows 49°10°, with 0.73 in19 mm of precipitation in a typical August.
- Record high
- 98°37° (2000)
- Record low
- 28°−2° (1962)
- Heating degree days
- 51
- Cooling degree days
- 77
Sinclair in September
Highs average 72°22° and lows 41°5°, with 0.89 in23 mm of precipitation in a typical September.
- Record high
- 95°35° (1998)
- Record low
- 8°−13° (1985)
- Heating degree days
- 263
- Cooling degree days
- 8
Sinclair in OctoberThis month
Highs average 57°14° and lows 30°−1°, with 0.68 in17 mm of precipitation in a typical October.
- Record high
- 82°28° (2025)
- Record low
- −20°−29° (2019)
- Heating degree days
- 663
- Cooling degree days
- 0
Sinclair in November
Highs average 42°5° and lows 21°−6°, with 0.47 in12 mm of precipitation in a typical November.
- Record high
- 70°21° (1999)
- Record low
- −24°−31° (2014)
- Heating degree days
- 1011
- Cooling degree days
- 0
Sinclair in December
Highs average 31°0° and lows 13°−11°, with 0.4 in10 mm of precipitation in a typical December.
- Record high
- 60°16° (2021)
- Record low
- −35°−37° (1990)
- Heating degree days
- 1331
- Cooling degree days
- 0