United States · 1991–2020 normal

Keystone in
December.

Typical December weather in Keystone: -0.2°C by day, -15.6°C at night, 22 mm of rain over 6.5 wet days. These are measured 1991–2020 station normals, not a forecast.

Typical high-0.2°C
Typical low-15.6°C
Rain22 mm
Wet days6.5

Comfort score 5 this month (July leads the year at 72). Daylight is calculated as 9 h 23 from latitude 39.60°.

Event window

Frost-level nights in December

The measured night-time normal is -15.6°C, so frost is typical rather than exceptional this month.

The evidence behind this page

One month,
from the same station.

Place identity
GeoNames 5427299
NOAA station
USC00052281 · DILLON 1 E
Station distance
4.8 km from the place centre
Coverage
Strong coverage · 30 usable years
Important limit
Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.