Newcastle weather by month
What a typical year looks like in Newcastle, Wyoming: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Newcastle, 1 km from Newcastle; records cover 1906–2026.
The year at a glance
- Precipitation a year
- 17.2 in436 mm
- Snow a year
- 39 in99 cm
- Last spring freeze
- May 14
- First fall freeze
- Sep 28
- Heating degree days
- 7,131
- Cooling degree days
- 711
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −11°−24° (heating, 99%) and 99°37° (cooling, 1%).
Month by month
Newcastle in January
Highs average 35°1° and lows 14°−10°, with 0.51 in13 mm of precipitation and 7 in17 cm of snow in a typical January.
- Record high
- 66°19° (1953)
- Record low
- −37°−38° (1930)
- Heating degree days
- 1259
- Cooling degree days
- 0
Newcastle in February
Highs average 38°3° and lows 16°−9°, with 0.67 in17 mm of precipitation and 8 in20 cm of snow in a typical February.
- Record high
- 69°21° (1995)
- Record low
- −33°−36° (1936)
- Heating degree days
- 1067
- Cooling degree days
- 0
Newcastle in March
Highs average 48°9° and lows 26°−4°, with 0.77 in20 mm of precipitation and 5 in12 cm of snow in a typical March.
- Record high
- 85°29° (2026)
- Record low
- −18°−28° (2019)
- Heating degree days
- 871
- Cooling degree days
- 0
Newcastle in April
Highs average 57°14° and lows 33°1°, with 1.7 in43 mm of precipitation and 5 in13 cm of snow in a typical April.
- Record high
- 91°33° (1910)
- Record low
- −13°−25° (1936)
- Heating degree days
- 596
- Cooling degree days
- 1
Newcastle in May
Highs average 66°19° and lows 43°6°, with 2.9 in74 mm of precipitation and 0.6 in1.5 cm of snow in a typical May.
- Record high
- 98°37° (1934)
- Record low
- 11°−12° (1954)
- Heating degree days
- 334
- Cooling degree days
- 18
Newcastle in June
Highs average 78°25° and lows 53°12°, with 2.7 in68 mm of precipitation in a typical June.
- Record high
- 105°41° (2002)
- Record low
- 28°−2° (1951)
- Heating degree days
- 92
- Cooling degree days
- 101
Newcastle in July
Highs average 87°30° and lows 60°16°, with 2.5 in65 mm of precipitation in a typical July.
- Record high
- 108°42° (1936)
- Record low
- 37°3° (1915)
- Heating degree days
- 13
- Cooling degree days
- 273
Newcastle in August
Highs average 86°30° and lows 59°15°, with 1.8 in46 mm of precipitation in a typical August.
- Record high
- 105°41° (1937)
- Record low
- 26°−3° (1910)
- Heating degree days
- 23
- Cooling degree days
- 241
Newcastle in September
Highs average 75°24° and lows 49°9°, with 1.2 in30 mm of precipitation and 0.2 in0.5 cm of snow in a typical September.
- Record high
- 101°38° (1940)
- Record low
- 12°−11° (1926)
- Heating degree days
- 163
- Cooling degree days
- 74
Newcastle in OctoberThis month
Highs average 59°15° and lows 36°2°, with 1.2 in31 mm of precipitation and 1.4 in3.6 cm of snow in a typical October.
- Record high
- 90°32° (1910)
- Record low
- −11°−24° (1925)
- Heating degree days
- 555
- Cooling degree days
- 3
Newcastle in November
Highs average 45°7° and lows 24°−4°, with 0.59 in15 mm of precipitation and 6 in14 cm of snow in a typical November.
- Record high
- 78°26° (1999)
- Record low
- −21°−29° (1985)
- Heating degree days
- 912
- Cooling degree days
- 0
Newcastle in December
Highs average 35°1° and lows 15°−9°, with 0.54 in14 mm of precipitation and 7 in17 cm of snow in a typical December.
- Record high
- 68°20° (1939)
- Record low
- −35°−37° (1983)
- Heating degree days
- 1246
- Cooling degree days
- 0