United States · 1991–2020 normal
Keystone in
September.
Typical September weather in Keystone: 19°C by day, -0.8°C at night, 36 mm of rain over 7.4 wet days. These are measured 1991–2020 station normals, not a forecast.
Typical high19°C
Typical low-0.8°C
Rain36 mm
Wet days7.4
Comfort score 51 this month (July leads the year at 72). Daylight is calculated as 12 h 24 from latitude 39.60°.
Event window
Frost-level nights in September
The measured night-time normal is -0.8°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.