Alta, Friday, 9 October, 02:12
Overcast. Feels like 40°. High 71°, low 38°.
Alta, Saturday, 10 October
Snow. High 48°, low 33°.
Alta, Sunday, 11 October
Snow. High 42°, low 31°.
Alta, Monday, 12 October
Light snow. High 49°, low 29°.
Alta, Tuesday, 13 October
Clear. High 52°, low 28°.
Alta, Wednesday, 14 October
Light rain. High 51°, low 32°.
Alta, Thursday, 15 October
Snow. High 41°, low 30°.
Alta, Friday, 16 October
Clear. High 56°, low 25°.
Alta, Saturday, 17 October
Overcast. High 61°, low 35°.
Alta, Sunday, 18 October
Clear. High 64°, low 37°.
Alta, Monday, 19 October
Clear. High 64°, low 37°.
Alta, Tuesday, 20 October
Clear. High 63°, low 38°.
Alta, Wednesday, 21 October
Clear. High 60°, low 39°.
Alta, Thursday, 22 October
Clear. High 65°, low 36°.
Alta, Friday, 23 October
Clear. High 66°, low 38°.
Alta, Saturday, 24 October
Clear. High 60°, low 40°.
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Alta, MT are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
They are real temperature extremes recorded in Alta, MT since 1960: the highest and lowest reading for each calendar date, with the year it happened.
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.