Yellowstone weather

The best months to visit Yellowstone are June, July, August, September. Late May through early June bison calving fills Lamar Valley with 'red dogs' and Beartooth Pass opens without July's traffic jams at Old Faithful.

July runs the highest averages in Yellowstone, with typical daytime highs of 22°C (71°F). July 28C afternoons draw crowds; locals (park staff, gateway town residents) hike Mt. Washburn at dawn or fish the Firehole where geothermal warms the water year-round.

January brings the lowest averages, with daytime highs near -6°C (21°F). January -30C mornings, most roads close except Mammoth-to-Cooke City; snowcoach tours to Old Faithful become the only access and bison herd on plowed roads.

February typically records the highest monthly rainfall — around 76mm on average. June afternoon thunderstorms drop hail on Hayden Valley and rangers close Grand Prismatic boardwalks when lightning is within 10 miles.

Yellowstone, United States has mild summers, freezing winters. Yellowstone sits on a supervolcano caldera — the ground literally breathes, and 2,000 earthquakes hit annually. The correct name for the local town is 'Gardiner' (north entrance) or 'West' (west entrance), never 'West Yellowstone town.' Bison kill more visitors than bears; the 25-yard rule exists because of Instagram tourists. Rangers hate the term 'buffalo' — they are bison, biologically distinct. The park closes most concessions by October 15 and the interior is a wildlife-only zone until May. Reserve Old Faithful Inn a year ahead; day-of-arrival gets you nothing. You can read the detailed month-by-month breakdown on this page.