Iliamna weather by month
What a typical year looks like in Iliamna, Alaska: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Iliamna Airport, 4 km from Iliamna; records cover 1920–2026.
The year at a glance
- Precipitation a year
- 25 in635 mm
- Snow a year
- Rare
- Last spring freeze
- May 13
- First fall freeze
- Sep 28
- Heating degree days
- 9,939
- Cooling degree days
- 9
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −19°−28° (heating, 99%) and 75°24° (cooling, 1%).
Month by month
Iliamna in January
Highs average 25°−4° and lows 12°−11°, with 0.9 in23 mm of precipitation in a typical January.
- Record high
- 57°14° (2014)
- Record low
- −47°−44° (1947)
- Heating degree days
- 1446
- Cooling degree days
- 0
Iliamna in February
Highs average 30°−1° and lows 16°−9°, with 1.1 in27 mm of precipitation in a typical February.
- Record high
- 50°10° (2025)
- Record low
- −46°−43° (1947)
- Heating degree days
- 1173
- Cooling degree days
- 0
Iliamna in March
Highs average 32°0° and lows 16°−9°, with 0.84 in21 mm of precipitation in a typical March.
- Record high
- 52°11° (1921)
- Record low
- −30°−34° (1922)
- Heating degree days
- 1280
- Cooling degree days
- 0
Iliamna in April
Highs average 43°6° and lows 29°−2°, with 0.83 in21 mm of precipitation in a typical April.
- Record high
- 67°19° (2005)
- Record low
- −30°−34° (1920)
- Heating degree days
- 868
- Cooling degree days
- 0
Iliamna in May
Highs average 55°13° and lows 38°3°, with 1.2 in30 mm of precipitation in a typical May.
- Record high
- 80°27° (2006)
- Record low
- 4°−16° (1949)
- Heating degree days
- 580
- Cooling degree days
- 0
Iliamna in June
Highs average 62°17° and lows 45°7°, with 1.5 in38 mm of precipitation in a typical June.
- Record high
- 91°33° (1953)
- Record low
- 28°−2° (1922)
- Heating degree days
- 341
- Cooling degree days
- 2
Iliamna in July
Highs average 65°18° and lows 51°10°, with 3.1 in78 mm of precipitation in a typical July.
- Record high
- 86°30° (2019)
- Record low
- 30°−1° (1921)
- Heating degree days
- 228
- Cooling degree days
- 5
Iliamna in August
Highs average 64°18° and lows 50°10°, with 4.1 in105 mm of precipitation in a typical August.
- Record high
- 83°28° (1968)
- Record low
- 22°−6° (1922)
- Heating degree days
- 259
- Cooling degree days
- 2
Iliamna in September
Highs average 56°13° and lows 43°6°, with 5 in127 mm of precipitation in a typical September.
- Record high
- 75°24° (2018)
- Record low
- 20°−7° (1921)
- Heating degree days
- 460
- Cooling degree days
- 0
Iliamna in OctoberThis month
Highs average 45°7° and lows 32°0°, with 2.8 in72 mm of precipitation in a typical October.
- Record high
- 66°19° (1976)
- Record low
- −4°−20° (1985)
- Heating degree days
- 823
- Cooling degree days
- 0
Iliamna in November
Highs average 33°1° and lows 21°−6°, with 2.2 in55 mm of precipitation in a typical November.
- Record high
- 52°11° (1986)
- Record low
- −20°−29° (1948)
- Heating degree days
- 1137
- Cooling degree days
- 0
Iliamna in December
Highs average 28°−2° and lows 15°−9°, with 1.5 in37 mm of precipitation in a typical December.
- Record high
- 49°9° (2014)
- Record low
- −31°−35° (1946)
- Heating degree days
- 1344
- Cooling degree days
- 0