Basalt, ID climate
Basalt has cold winters and warm summers, with very little rain. A typical July afternoon reaches 87°, a January night drops to 14°, and about 15 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Basalt feels like
Winter
Spring
Summer
Fall
Basalt 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 31° | 14° | 0.8" | 6.0" | 8 | 14° – 30° |
| February | 36° | 17° | 0.7" | 2.2" | 7 | 17° – 37° |
| March | 48° | 26° | 0.9" | 0.3" | 7 | 30° – 43° |
| April | 58° | 32° | 1.2" | 0.7" | 9 | 40° – 50° |
| May | 68° | 40° | 1.7" | 0 | 8 | 48° – 58° |
| June | 77° | 46° | 1.1" | 0 | 6 | 56° – 68° |
| July | 87° | 52° | 0.5" | 0 | 3 | 59° – 75° |
| August | 86° | 50° | 0.7" | 0 | 3 | 62° – 72° |
| September | 75° | 42° | 1.0" | 0 | 4 | 55° – 63° |
| October | 60° | 32° | 1.0" | 0.8" | 6 | 37° – 53° |
| November | 44° | 23° | 0.7" | 1.4" | 5 | 25° – 40° |
| December | 32° | 15° | 0.9" | 3.3" | 8 | 17° – 30° |
| Year | 58° | 33° | 11.2" | 14.7" | 74 |
“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 Basalt
Basalt gets 11 inches of rain and melted snow a year. May is the wettest month and July the driest. Rain or snow falls on about 74 days a year.
About 114 frost-free days a year
In half of years the last 32° night comes by May 23 and the first one by September 20. That leaves about 114 frost-free days for gardens, shorter than 98% of U.S. towns.
Heating and cooling a home in Basalt
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Basalt, 97% of that work is heating and 3% 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 Basalt 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 Basalt averaged 1.4° warmer than the 1900s. The biggest change is in March (+3.5°). The shift is larger than in 66% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Basalt’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 17° to 37°. September is the most reliable, staying within 8°.
Common questions about Basalt’s climate
What is the coldest month in Basalt?
January, with a typical high of 31° and a low of 14°.
What is the hottest month in Basalt?
July, with a typical high of 87° and a low of 52°. About 26 days a year reach 90°.
How much snow does Basalt get?
About 15 inches in a normal winter, most of it in January.
When is the first frost in Basalt?
In half of years the first 32° night comes by September 20, and the last spring frost by May 23.
What is the rainiest month in Basalt?
May, with 1.7 inches of rain and melted snow. The year totals 11 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Basalt itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Blackfoot Fire Dept, ID (12 mi, snow) and Idaho Falls Fanning Fld, ID (15 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.