American Falls weather by month
What a typical year looks like in American Falls, Idaho: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at American Falls, 5 km from American Falls; records cover 1892–2025.
The year at a glance
- Precipitation a year
- 11.1 in282 mm
- Snow a year
- Rare
- Last spring freeze
- May 10
- First fall freeze
- Oct 3
- Heating degree days
- 6,505
- Cooling degree days
- 608
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −2°−19° (heating, 99%) and 97°36° (cooling, 1%).
Month by month
American Falls in January
Highs average 35°1° and lows 19°−7°, with 0.96 in24 mm of precipitation in a typical January.
- Record high
- 59°15° (2003)
- Record low
- −38°−39° (1949)
- Heating degree days
- 1190
- Cooling degree days
- 0
American Falls in February
Highs average 39°4° and lows 21°−6°, with 0.68 in17 mm of precipitation in a typical February.
- Record high
- 69°21° (1901)
- Record low
- −30°−34° (1985)
- Heating degree days
- 978
- Cooling degree days
- 0
American Falls in March
Highs average 52°11° and lows 29°−2°, with 1 in26 mm of precipitation in a typical March.
- Record high
- 78°26° (1986)
- Record low
- −14°−26° (1893)
- Heating degree days
- 761
- Cooling degree days
- 0
American Falls in April
Highs average 60°16° and lows 35°2°, with 1.3 in33 mm of precipitation in a typical April.
- Record high
- 88°31° (2012)
- Record low
- 6°−14° (1936)
- Heating degree days
- 525
- Cooling degree days
- 0
American Falls in May
Highs average 71°22° and lows 43°6°, with 1.5 in39 mm of precipitation in a typical May.
- Record high
- 99°37° (1919)
- Record low
- 13°−11° (1919)
- Heating degree days
- 266
- Cooling degree days
- 15
American Falls in June
Highs average 79°26° and lows 50°10°, with 1.2 in29 mm of precipitation in a typical June.
- Record high
- 103°39° (1900)
- Record low
- 19°−7° (1919)
- Heating degree days
- 97
- Cooling degree days
- 77
American Falls in July
Highs average 90°32° and lows 56°14°, with 0.53 in13 mm of precipitation in a typical July.
- Record high
- 106°41° (1925)
- Record low
- 23°−5° (1903)
- Heating degree days
- 7
- Cooling degree days
- 267
American Falls in August
Highs average 88°31° and lows 55°13°, with 0.49 in12 mm of precipitation in a typical August.
- Record high
- 106°41° (1893)
- Record low
- 26°−3° (1911)
- Heating degree days
- 15
- Cooling degree days
- 208
American Falls in September
Highs average 77°25° and lows 46°8°, with 0.81 in21 mm of precipitation in a typical September.
- Record high
- 100°38° (1899)
- Record low
- 16°−9° (1911)
- Heating degree days
- 142
- Cooling degree days
- 39
American Falls in OctoberThis month
Highs average 61°16° and lows 36°2°, with 0.92 in23 mm of precipitation in a typical October.
- Record high
- 89°32° (2010)
- Record low
- 3°−16° (2019)
- Heating degree days
- 504
- Cooling degree days
- 2
American Falls in November
Highs average 47°8° and lows 27°−3°, with 0.83 in21 mm of precipitation in a typical November.
- Record high
- 85°29° (1899)
- Record low
- −23°−31° (1896)
- Heating degree days
- 850
- Cooling degree days
- 0
American Falls in December
Highs average 35°1° and lows 20°−7°, with 0.87 in22 mm of precipitation in a typical December.
- Record high
- 62°17° (1980)
- Record low
- −26°−32° (1924)
- Heating degree days
- 1170
- Cooling degree days
- 0