Fairbanks weather in September

Forum posters describe January in Fairbanks as brutally cold, with a typical average temperature around -20C and real cold snaps capable of dropping to -40C or worse, alongside very limited daylight - around 6 to 6.5 hours by late January, with sunrise not until roughly 10:30am mid-month. Posters consistently name the clear, cold skies that come with this deep cold as exactly why Fairbanks draws aurora-hunters in January, with one poster citing roughly 80% odds of seeing the northern lights across a 3-night stay, though sightings are never guaranteed on any single night. Posters consistently recommend serious cold-weather gear and generally advise against inexperienced winter driving up into Alaska's interior. Posters generally recommend dog sledding, snowmobiling, a soak at Chena Hot Springs, or museums to fill daylight hours while waiting for clear, aurora-viewing nights.

July is Fairbanks' warm month — the forum puts it in the 20s°C with occasional pushes into the 30s, against a record average high of 23 — but the thing people actually come for is the light: it does not get dark at all, sunset lands around 11:45pm, and the daylight figure is roughly twenty hours. That same light rules out the other reason people come to Fairbanks. There is no darkness in July, so the odds of seeing the aurora are zero; aurora season here runs 21 August to 21 April. The other caveat locals supply is that mid-July to mid-August is what they call monsoon season, the wettest stretch of the summer, and the record agrees at ten rainy days.