Altona, CO climate
Altona has chilly, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 84°, a January night drops to 20°, and about 184 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Altona feels like
Winter
Spring
Summer
Fall
Altona weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 44° | 20° | 0.6" | 15.8" | 9 | 31 | 25° – 38° |
| February | 44° | 21° | 0.7" | 28.0" | 12 | 29 | 28° – 40° |
| March | 52° | 28° | 1.5" | 29.9" | 12 | 29 | 34° – 46° |
| April | 58° | 33° | 2.3" | 34.9" | 13 | 19 | 40° – 50° |
| May | 67° | 42° | 2.8" | 17.9" | 16 | 6 | 49° – 58° |
| June | 78° | 50° | 1.9" | 0.1" | 10 | 0 | 60° – 70° |
| July | 84° | 56° | 2.1" | 0 | 15 | 0 | 66° – 74° |
| August | 82° | 54° | 1.9" | 0 | 14 | 0 | 64° – 72° |
| September | 75° | 47° | 1.6" | 0.7" | 10 | 1 | 56° – 65° |
| October | 62° | 36° | 1.2" | 18.1" | 10 | 8 | 42° – 55° |
| November | 51° | 28° | 0.9" | 13.5" | 8 | 19 | 30° – 46° |
| December | 43° | 21° | 0.6" | 24.6" | 11 | 29 | 25° – 35° |
| Year | 62° | 36° | 17.9" | 183.5" | 140 | 169 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Altona
Altona gets 18 inches of rain and melted snow a year. May is the wettest month and December the driest. Rain or snow falls on about 140 days a year. Snow covers the ground about 169 days of the year.
About 151 frost-free days a year
In half of years the last 32° night comes by May 6 and the first one by October 5. That leaves about 151 frost-free days for gardens, shorter than 80% of U.S. towns.
Heating and cooling a home in Altona
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Altona, 90% of that work is heating and 10% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Altona compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Altona averaged 1.4° warmer than the 1900s. The biggest change is in March (+3.1°). The shift is larger than in 62% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Altona’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 30° to 46°. August is the most reliable, staying within 8°.
Common questions about Altona’s climate
What is the coldest month in Altona?
January, with a typical high of 44° and a low of 20°.
What is the hottest month in Altona?
July, with a typical high of 84° and a low of 56°. About 33 days a year reach 90°.
How much snow does Altona get?
About 184 inches in a normal winter, most of it in April.
When is the first frost in Altona?
In half of years the first 32° night comes by October 5, and the last spring frost by May 6.
What is the rainiest month in Altona?
May, with 2.8 inches of rain and melted snow. The year totals 18 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Altona itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Ward 4.6 Ne, CO (8 mi, snow) and Boulder, CO (9 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.