Anchorage, Alaska's largest city, sits on a coastal plain at the head of Cook Inlet in south-central Alaska, hemmed in by the Chugach Mountains at approximately 61.22°N, 149.90°W. Its far-northern position gives it a subarctic climate (Köppen Dfb/Dfc) — with cool summers and long, cold, snowy winters — though the sea and mountains moderate it considerably.

Summer, from June to August, is short and cool, with July the warmest month — average highs around 18–19°C — and genuinely hot days almost unknown. What the season lacks in warmth it makes up in daylight: around the solstice the sun barely sets, giving nineteen hours of light. Precipitation increases into autumn, with September the wettest month.

Winter, from November to March, is long, cold and snowy, with January the coldest month — average highs around -6°C and lows near -13°C, and cold snaps well below -20°C. Anchorage receives around 190 cm of snow in an average winter. Daylight shrinks to only about five hours at the solstice, though the aurora may light the long nights.

Anchorage receives around 400–840 mm of precipitation a year depending on the measuring station, relatively modest for a coastal city because the Chugach and Kenai mountains shelter it, with September the wettest month and April the driest; much of the cold-season total falls as snow, around 190 cm a year. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Anchorage's mountain-sheltered position on Cook Inlet makes it far milder and drier than much of coastal Alaska — the Gulf coast to the southeast receives several metres of precipitation a year. The city's defining rhythm is light: from nineteen hours of midsummer sun to barely five in December.

To follow any single measurement in Anchorage more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.